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jclaytons |
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-- Package of async_syscon components
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--
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.NUMERIC_STD.ALL;
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package async_syscon_pack is
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-- A system controller with an 8-bit parallel ASCII interface
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component ascii_syscon
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generic (
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ADR_DIGITS : natural; -- # of hex digits for address
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DAT_DIGITS : natural; -- # of hex digits for data
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QTY_DIGITS : natural; -- # of hex digits for quantity
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CMD_BUFFER_SIZE : natural; -- # of chars in the command buffer
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WATCHDOG_VALUE : natural; -- # of sys_clks before ack is expected
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DISPLAY_FIELDS : natural -- # of fields/line
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);
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port (
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sys_rst_n : in std_logic;
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sys_clk : in std_logic;
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sys_clk_en : in std_logic;
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-- Parallel ASCII I/O
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cmd_char_i : in unsigned(7 downto 0);
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cmd_we_i : in std_logic;
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cmd_ack_o : out std_logic;
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cmd_echo_o : out std_logic;
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resp_char_o : out unsigned(7 downto 0);
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resp_cyc_o : out std_logic;
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resp_ack_i : in std_logic;
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cmd_done_o : out std_logic;
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-- Master Bus IO
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master_bg_i : in std_logic;
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master_ack_o : out std_logic;
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master_adr_i : in unsigned(4*ADR_DIGITS-1 downto 0);
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master_dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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master_dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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master_stb_i : in std_logic;
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master_we_i : in std_logic;
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master_br_o : out std_logic;
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-- System Bus IO
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ack_i : in std_logic;
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err_i : in std_logic;
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dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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rst_o : out std_logic;
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stb_o : out std_logic;
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cyc_o : out std_logic;
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adr_o : out unsigned(4*ADR_DIGITS-1 downto 0);
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we_o : out std_logic
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);
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end component;
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-- ascii_syscon mounted with a UART interface
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component async_syscon
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generic (
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ECHO_COMMANDS : natural; -- set nonzero to echo back command characters
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ADR_DIGITS : natural; -- # of hex digits for address
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DAT_DIGITS : natural; -- # of hex digits for data
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QTY_DIGITS : natural; -- # of hex digits for quantity
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CMD_BUFFER_SIZE : natural; -- # of chars in the command buffer
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WATCHDOG_VALUE : natural; -- # of sys_clks before ack is expected
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DISPLAY_FIELDS : natural -- # of fields/line
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);
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port (
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sys_rst_n : in std_logic;
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sys_clk : in std_logic;
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sys_clk_en : in std_logic;
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-- rate and parity
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parity_i : in unsigned(1 downto 0); -- 0=none, 1=even, 2=odd
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baud_clk_i : in std_logic; -- At 1x the desired baud rate, can be squarewave or pulses.
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baud_lock_i : in std_logic; -- '1' Indicates baud clock is stable and ready.
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-- Serial IO
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cmd_i : in std_logic;
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resp_o : out std_logic;
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cmd_done_o : out std_logic;
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-- Master Bus IO
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master_bg_i : in std_logic;
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master_ack_o : out std_logic;
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master_adr_i : in unsigned(4*ADR_DIGITS-1 downto 0);
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master_dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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master_dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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master_stb_i : in std_logic;
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master_we_i : in std_logic;
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master_br_o : out std_logic;
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-- System Bus IO
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ack_i : in std_logic;
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err_i : in std_logic;
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dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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rst_o : out std_logic;
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stb_o : out std_logic;
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cyc_o : out std_logic;
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adr_o : out unsigned(4*ADR_DIGITS-1 downto 0);
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we_o : out std_logic
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);
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end component;
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end async_syscon_pack;
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package body async_syscon_pack is
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end async_syscon_pack;
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---------------------------------------------------------------------------------------
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--
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-- Author: John Clayton
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-- Date : Dec. 27, 2013
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-- Update: 12/27/13 copied async_syscon module, removed the serial interface.
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-- 02/05/14 Added line feed as a whitespace character, to
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-- char_is_whitespace.
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-- 02/06/14 Made resp_cyc a direct function of the state machine state.
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-- This allows it to be asserted even when resp_ack_i is tied
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-- to '1' all the time...
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-- 02/13/14 Made a slight enhancement to the processing of comments.
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-- Previously, all comments were treated as "full line"
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-- comments, causing any valid commands preceding the
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-- comment to be ignored, since the entire line was being
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-- ignored. I realized that a very small value
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-- check on cmd_ptr could differentiate between full line
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-- comments, and ones for which there might actually be
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-- a valid command. The enhanced design can process the
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-- valid commands.
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-- 02/14/14 Happy Valentine's Day! Fixed a "wacky" bug which caused
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-- an extra digit to be displayed for address and data fields.
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-- Added "0" command suffix, which prevents the bus address
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-- from incrementing during read, write and fill operations.
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-- It's useful for working with FIFOs that have read/write
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-- ports mapped to a single address, instead of a whole
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-- range of addresses.
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-- 02/27/14 Refined the CHECK_SUFFICES state by adding a jump to
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-- START_EXECUTION when ENTER_CHAR is found in the suffix
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-- position, thus preserving the "repeat last read with
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-- previous address and quantity" function.
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--
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-- Description
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---------------------------------------------------------------------------------------
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-- This is an 8-bit parallel ASCII character driven interface to a system
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-- controller driving a "Wishbone" type of parallel system bus.
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--
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-- Specifically, the unit allows the user to send text commands to the
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-- "ascii_syscon" unit, in order to generate read and write cycles on the
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-- Wishbone compatible bus. The command structure is quite terse and spartan
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-- in nature, this is for the sake of the logic itself.
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--
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-- The command line buffer is small enough to be implemented without the use
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-- of dedicated BRAM memory blocks, and the menus and command responses were
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-- kept as small as possible. In most cases, the responses from the unit to
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-- the user consist of a "newline" and one or two visible characters. The
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-- command structure consists of the following commands and responses:
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--
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-- Command Syntax Purpose
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-- --------------- ---------------------------------------
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-- w aaaa dddd dddd dddd... Write data items "dddd" starting at address "aaaa"
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-- using sequential addresses.
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-- (If the data field is missing, nothing is done).
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-- w0 aaaa dddd dddd dddd... Write data items "dddd" at address "aaaa"
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-- without incrementing the address.
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-- (If the data field is missing, nothing is done).
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-- f aaaa dddd xx "Fill": Write data "dddd" starting at address "aaaa"
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-- perform this "xx" times at sequential addresses.
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-- (The quantity field is optional, default is 1).
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-- f0 aaaa dddd xx "Fill": Write data "dddd" starting at address "aaaa"
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-- perform this "xx" times at the same address.
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-- (The quantity field is optional, default is 1).
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-- r aaaa xx Read data starting from address "aaaa."
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-- Perform this "xx" times at sequential addresses.
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-- (The quantity field is optional, default is 1).
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-- r0 aaaa xx Read data from address "aaaa."
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-- Perform this "xx" times, using the same address.
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-- (The quantity field is optional, default is 1).
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-- i Send a reset pulse to the system. (initialize).
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--
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-- <COMMENT_CHAR> "Single Line" type Comment token. Characters
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-- after the token are ignored until <ENTER>.
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-- This enables applications which send
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-- files to the unit to include comments for
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-- display and as an aid to understanding.
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-- The comment token is a constant, change it
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-- to be whatever makes sense!
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--
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-- Response from async_syscon Meaning
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-- -------------------------- ---------------------------------------
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-- OK Command received and performed. No errors.
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-- ? Command buffer full, without receiving "enter."
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-- C? Command not recognized.
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-- A? Address field syntax error.
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-- D? Data field syntax error.
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-- Q? Quantity field syntax error.
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-- ! No "ack_i", or else "err_i" received from bus.
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-- B! No "bg_i" received from master.
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--
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-- NOTES on the operation of this unit:
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--
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-- - The unit generates a command prompt which is "-> ".
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-- - Capitalization is not important.
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-- - Each command is terminated by the "enter" key (0x0d character).
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-- Commands are executed as soon as "enter" is received.
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-- - Trailing parameters need not be re-entered. Their values will
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-- remain the same as their previous settings.
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-- - Use of the backspace key is supported, so mistakes can be corrected.
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-- - The length of the command line is limited to a fixed number of
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-- characters, as configured by parameter.
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-- - Fields are separated by white space, including "tab" and/or "space"
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-- - All numerical fields are interpreted as hexadecimal numbers.
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-- Decimal is not supported.
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-- - Numerical field values are retained between commands. If a "r" is issued
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-- without any fields following it, the previous values will be used. A
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-- set of "quantity" reads will take place at sequential addresses.
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-- If a "f" is issued without any fields following it, the previous data
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-- value will be written "quantity" times at sequential addresses, starting
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-- from the next location beyond where the last command ended.
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-- - If the user does not wish to use "ack" functionality, simply tie the
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-- "ack_i" input to logic 1, and then the ! response will never be generated.
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-- - The data which is read in by the "r" command is displayed using lines
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-- which begin with the address, followed by the data fields. The number
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-- of data fields displayed per line (following the address) is adjustable
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-- by setting a parameter. No other display format adjustments can be made.
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-- - There is currently only a single watchdog timer. It begins to count at
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-- the time the "enter" is received to execute a command. If the bus is granted
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-- and the ack is received before the expiration of the timer, then the
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-- cycle will complete normally. Therefore, the watchdog timeout value
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-- needs to include time for the request and granting of the bus, in
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-- addition to the time needed for the actual bus cycle to complete.
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--
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--
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-- Currently, there is only a single indicator (stb_o) generated during bus
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-- output cycles which are generated from this unit.
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-- The user can easily implement decoding logic based upon adr_o and stb_o
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-- which would serve as multiple "stb_o" type signals for different cores
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-- which would be sharing the same bus.
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--
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-- The data bus supported by this module is separate input/output type of bus.
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-- However, if a single tri-state dat_io bus is desired, it can be added
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-- to the module without too much trouble. Supposedly the only difference
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-- between the two forms of data bus is that one of them avoids using tri-state
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-- at the cost of doubling the number of interconnects used to carry data back
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-- and forth... Some people say that tri-state should be avoided for use
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-- in internal busses in ASICs. Maybe they are right.
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-- But in FPGAs tri-state seems to work pretty well, even for internal busses.
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--
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-- Parameters are provided to configure the width of the different command
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-- fields. To simplify the logic for binary to hexadecimal conversion, these
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-- parameters allow adjustment in units of 1 hex digit, not anything smaller.
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-- If your bus has 10 bits, for instance, simply set the address width to 3
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-- which produces 12 bits, and then just don't use the 2 msbs of address
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-- output.
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--
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-- No support for the optional Wishbone "retry" (rty_i) input is provided at
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-- this time.
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-- No support for "tagn_o" bits is provided at this time, although a register
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-- might be added external to this module in order to implement to tag bits.
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-- No BLOCK or RMW cycles are supported currently, so cyc_o is equivalent to
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-- stb_o...
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-- The output busses are not tri-stated. The user may add tri-state buffers
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-- external to the module, using "stb_o" to enable the buffer outputs.
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--
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---------------------------------------------------------------------------------------
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.NUMERIC_STD.ALL;
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library work;
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use work.convert_pack.all;
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use work.async_syscon_pack.all;
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entity ascii_syscon is
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generic (
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ADR_DIGITS : natural := 4; -- # of hex digits for address
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DAT_DIGITS : natural := 4; -- # of hex digits for data
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QTY_DIGITS : natural := 2; -- # of hex digits for quantity
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CMD_BUFFER_SIZE : natural := 32; -- # of chars in the command buffer
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WATCHDOG_VALUE : natural := 200; -- # of sys_clks before ack is expected
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DISPLAY_FIELDS : natural := 8 -- # of fields/line
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);
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port (
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sys_rst_n : in std_logic;
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sys_clk : in std_logic;
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sys_clk_en : in std_logic;
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-- Parallel ASCII I/O
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cmd_char_i : in unsigned(7 downto 0);
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cmd_we_i : in std_logic;
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cmd_ack_o : out std_logic;
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cmd_echo_o : out std_logic;
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resp_char_o : out unsigned(7 downto 0);
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resp_cyc_o : out std_logic;
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resp_ack_i : in std_logic;
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cmd_done_o : out std_logic;
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-- Master Bus IO
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master_bg_i : in std_logic;
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master_ack_o : out std_logic;
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master_adr_i : in unsigned(4*ADR_DIGITS-1 downto 0);
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master_dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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master_dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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master_stb_i : in std_logic;
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master_we_i : in std_logic;
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master_br_o : out std_logic;
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-- System Bus IO
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ack_i : in std_logic;
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err_i : in std_logic;
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dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
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dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
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rst_o : out std_logic;
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|
|
stb_o : out std_logic;
|
320 |
|
|
cyc_o : out std_logic;
|
321 |
|
|
adr_o : out unsigned(4*ADR_DIGITS-1 downto 0);
|
322 |
|
|
we_o : out std_logic
|
323 |
|
|
);
|
324 |
|
|
end ascii_syscon;
|
325 |
|
|
|
326 |
|
|
library IEEE;
|
327 |
|
|
use IEEE.STD_LOGIC_1164.ALL;
|
328 |
|
|
use IEEE.NUMERIC_STD.ALL;
|
329 |
|
|
|
330 |
|
|
architecture beh of ascii_syscon is
|
331 |
|
|
|
332 |
|
|
-- Constants
|
333 |
|
|
constant CMD_PTR_BITS : natural := bit_width(CMD_BUFFER_SIZE);
|
334 |
|
|
constant DISPLAY_FIELD_COUNT_BITS : natural := bit_width(DISPLAY_FIELDS);
|
335 |
|
|
constant DISPLAY_ADR_DIGIT_COUNT_BITS : natural := bit_width(ADR_DIGITS);
|
336 |
|
|
constant DISPLAY_DAT_DIGIT_COUNT_BITS : natural := bit_width(DAT_DIGITS);
|
337 |
|
|
constant WATCHDOG_TIMER_BITS : natural := timer_width(WATCHDOG_VALUE);
|
338 |
|
|
|
339 |
|
|
constant BACKSPACE_CHAR : unsigned := "00001000";
|
340 |
|
|
constant ENTER_CHAR : unsigned := "00001101";
|
341 |
|
|
constant COMMENT_CHAR : unsigned := "00100011"; -- '#' character
|
342 |
|
|
--constant COMMENT_CHAR : unsigned := "00101101"; -- '-' character
|
343 |
|
|
|
344 |
|
|
-- Internal signal declarations
|
345 |
|
|
-- For the state machine
|
346 |
|
|
type FSM_STATE_TYPE is (IDLE, SEND_WELCOME_STRING, SEND_OK, SEND_PROMPT,
|
347 |
|
|
CHECK_NEW_CHAR, SEND_CRLF, PARSE_ERR_INDICATOR_CRLF,
|
348 |
|
|
ERR_INDICATOR, BG_ERR_INDICATOR, SEND_QUESTION,
|
349 |
|
|
SCAN_CMD, CHECK_SUFFICES, SCAN_ADR_WHITESPACE,
|
350 |
|
|
GET_ADR_FIELD, SCAN_DAT_WHITESPACE, GET_DAT_FIELD,
|
351 |
|
|
SCAN_QTY_WHITESPACE, GET_QTY_FIELD, START_EXECUTION,
|
352 |
|
|
REQUEST_BUS, EXECUTE, DISPLAY_PREP, DISPLAY_ADR,
|
353 |
|
|
DISPLAY_SEPARATOR, DISPLAY_DAT, DISPLAY_SPACE,
|
354 |
|
|
DISPLAY_CRLF, POST_FILL_CYCLE);
|
355 |
|
|
|
356 |
|
|
signal fsm_state : FSM_STATE_TYPE;
|
357 |
|
|
|
358 |
|
|
signal watchdog_timer_done : std_logic; -- High when watchdog timer is expired
|
359 |
|
|
signal char_is_whitespace : std_logic; -- High when cmd_buffer[char_count] is whitespace.
|
360 |
|
|
signal char_is_num : std_logic; -- High when cmd_buffer[char_count] is 0..9
|
361 |
|
|
signal char_is_a_f : std_logic; -- High when cmd_buffer[char_count] is a..f
|
362 |
|
|
signal char_is_hex : std_logic; -- High when cmd_buffer[char_count] is a hex char.
|
363 |
|
|
signal msg_pointer : unsigned(4 downto 0); -- Determines message position or address.
|
364 |
|
|
signal msg_select : unsigned(4 downto 0); -- selection of msg_pointer or display value
|
365 |
|
|
signal hex_digit : unsigned(3 downto 0); -- This is the digit to be stored.
|
366 |
|
|
|
367 |
|
|
signal msg_char : unsigned(7 downto 0); -- Selected response message character.
|
368 |
|
|
signal comment_area : std_logic;
|
369 |
|
|
|
370 |
|
|
-- For the buses
|
371 |
|
|
signal adr_ptr : unsigned(4*ADR_DIGITS-1 downto 0); -- = adr_sr + adr_offset
|
372 |
|
|
|
373 |
|
|
signal stb_l : std_logic; -- "local" stb signal (to distinguish from stb_o)
|
374 |
|
|
signal we_l : std_logic; -- "local" we signal (to distinguish from we_o)
|
375 |
|
|
|
376 |
|
|
signal display_adr_sr : unsigned(4*ADR_DIGITS-1 downto 0); -- sr for printing addresses
|
377 |
|
|
signal adr_sr : unsigned(4*ADR_DIGITS-1 downto 0); -- "nibble" shift register
|
378 |
|
|
signal dat_sr : unsigned(4*DAT_DIGITS-1 downto 0); -- "nibble" shift register
|
379 |
|
|
signal qty_sr : unsigned(4*QTY_DIGITS-1 downto 0); -- "nibble" shift register
|
380 |
|
|
|
381 |
|
|
-- The command register has these values
|
382 |
|
|
type CMD_REG_TYPE is (INIT, READ, FILL, WRITE);
|
383 |
|
|
signal command : CMD_REG_TYPE;
|
384 |
|
|
|
385 |
|
|
-- For the command buffer
|
386 |
|
|
signal cmd_ptr : unsigned(CMD_PTR_BITS-1 downto 0); -- Offset from start of command.
|
387 |
|
|
--signal rd_cmd_ptr : unsigned(CMD_PTR_BITS-1 downto 0); -- Latched cmd_ptr, use to infer BRAM.
|
388 |
|
|
type cmd_array_type is
|
389 |
|
|
array (integer range 0 to CMD_BUFFER_SIZE-1) of unsigned(7 downto 0);
|
390 |
|
|
|
391 |
|
|
signal cmd_buffer : cmd_array_type;
|
392 |
|
|
signal cmd_char : unsigned(7 downto 0);
|
393 |
|
|
signal lc_cmd_char : unsigned(7 downto 0); -- Lowercase version of cmd_char
|
394 |
|
|
signal adr_offset : unsigned(4*QTY_DIGITS-1 downto 0); -- counts from 0 to qty_sr
|
395 |
|
|
signal adr_freeze : std_logic; -- When set, prevents adr_offset from incrementing
|
396 |
|
|
|
397 |
|
|
signal resp_cyc : std_logic; -- high for response type states
|
398 |
|
|
signal resp_cyc_l : std_logic;
|
399 |
|
|
signal resp_cyc_mask : std_logic; -- Used to lower resp_cyc_o for one clock cycle, upon acknowledgement.
|
400 |
|
|
|
401 |
|
|
-- For various counters
|
402 |
|
|
signal display_field_count : unsigned(DISPLAY_FIELD_COUNT_BITS-1 downto 0); -- "fields displayed"
|
403 |
|
|
signal display_adr_digit_count : unsigned(DISPLAY_ADR_DIGIT_COUNT_BITS-1 downto 0); -- "digits displayed"
|
404 |
|
|
signal display_dat_digit_count : unsigned(DISPLAY_DAT_DIGIT_COUNT_BITS-1 downto 0); -- "digits displayed"
|
405 |
|
|
signal watchdog_timer_count : unsigned(WATCHDOG_TIMER_BITS-1 downto 0);
|
406 |
|
|
|
407 |
|
|
----------------------------------------------------------------------------
|
408 |
|
|
-- Component Declarations
|
409 |
|
|
----------------------------------------------------------------------------
|
410 |
|
|
|
411 |
|
|
----------------------------------------------------------------------------
|
412 |
|
|
begin
|
413 |
|
|
|
414 |
|
|
-- In this module, command characters are accepted immediately but only when in the CHECK_NEW_CHAR state.
|
415 |
|
|
cmd_ack_o <= '1' when cmd_we_i='1' and fsm_state=CHECK_NEW_CHAR else '0';
|
416 |
|
|
|
417 |
|
|
-- Provide response character cycle active signal
|
418 |
|
|
resp_cyc <= '1' when fsm_state=DISPLAY_CRLF or
|
419 |
|
|
fsm_state=DISPLAY_SPACE or
|
420 |
|
|
fsm_state=DISPLAY_DAT or
|
421 |
|
|
fsm_state=DISPLAY_SEPARATOR or
|
422 |
|
|
fsm_state=DISPLAY_ADR or
|
423 |
|
|
fsm_state=SEND_QUESTION or
|
424 |
|
|
fsm_state=ERR_INDICATOR or
|
425 |
|
|
fsm_state=PARSE_ERR_INDICATOR_CRLF or
|
426 |
|
|
fsm_state=BG_ERR_INDICATOR or
|
427 |
|
|
fsm_state=SEND_CRLF or
|
428 |
|
|
fsm_state=SEND_PROMPT or
|
429 |
|
|
fsm_state=SEND_OK or
|
430 |
|
|
fsm_state=SEND_WELCOME_STRING else
|
431 |
|
|
'0';
|
432 |
|
|
-- Implement the "courtesy" of lowering resp_cyc_o for one cycle after resp_ack_i is recognized.
|
433 |
|
|
-- This increases the amount of time needed for data transfer, and some would say it is needless,
|
434 |
|
|
-- since a "burst" type transfer also can work. Since burst transfers were not intended here,
|
435 |
|
|
-- this is being done anyway. You see, burst transfers can "tie up" bus arbiters for the entire
|
436 |
|
|
-- burst, which is not desirable in this design.
|
437 |
|
|
resp_cyc_l <= '1' when resp_cyc='1' and resp_cyc_mask='0' else '0';
|
438 |
|
|
resp_cyc_o <= resp_cyc_l;
|
439 |
|
|
|
440 |
|
|
resp_cyc_mask_proc : process(sys_clk,sys_rst_n)
|
441 |
|
|
variable i : natural;
|
442 |
|
|
begin
|
443 |
|
|
if (sys_rst_n='0') then
|
444 |
|
|
resp_cyc_mask <= '0';
|
445 |
|
|
elsif (sys_clk'event and sys_clk='1') then
|
446 |
|
|
if (sys_clk_en='1') then
|
447 |
|
|
resp_cyc_mask <= '0'; -- Default value
|
448 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
449 |
|
|
resp_cyc_mask <= '1';
|
450 |
|
|
end if;
|
451 |
|
|
end if;
|
452 |
|
|
end if;
|
453 |
|
|
end process;
|
454 |
|
|
|
455 |
|
|
|
456 |
|
|
-- Provide command echo indication, to allow ASCII response data to be
|
457 |
|
|
-- echoed or not, as desired.
|
458 |
|
|
cmd_echo_o <= '1' when fsm_state=CHECK_NEW_CHAR else '0';
|
459 |
|
|
|
460 |
|
|
-- Provide parallel ASCII response data
|
461 |
|
|
resp_char_o <= msg_char;
|
462 |
|
|
|
463 |
|
|
-- Select which bus signals get used on the system bus
|
464 |
|
|
adr_o <= adr_ptr when (master_bg_i='1') else master_adr_i;
|
465 |
|
|
we_o <= we_l when (master_bg_i='1') else master_we_i;
|
466 |
|
|
stb_o <= stb_l when (master_bg_i='1') else master_stb_i;
|
467 |
|
|
cyc_o <= stb_l when (master_bg_i='1') else master_stb_i; -- Separate cyc_o is not yet supported!
|
468 |
|
|
|
469 |
|
|
dat_o <= dat_sr when (master_bg_i='1' and we_l='1' and stb_l='1') else master_dat_i;
|
470 |
|
|
master_dat_o <= dat_i;
|
471 |
|
|
master_ack_o <= ack_i when master_bg_i='0' else '0';
|
472 |
|
|
|
473 |
|
|
-- This forms the adress pointer which is used on the bus.
|
474 |
|
|
adr_ptr <= adr_sr + adr_offset when adr_freeze='0' else adr_sr;
|
475 |
|
|
|
476 |
|
|
-- This is the ROM for the ASCII characters to be transmitted.
|
477 |
|
|
-- Choose which value to use
|
478 |
|
|
msg_select <= '0' & display_adr_sr(4*ADR_DIGITS-1 downto 4*(ADR_DIGITS-1)) when fsm_state=DISPLAY_ADR else
|
479 |
|
|
'0' & dat_sr(4*DAT_DIGITS-1 downto 4*(DAT_DIGITS-1)) when fsm_state=DISPLAY_DAT else
|
480 |
|
|
msg_pointer;
|
481 |
|
|
with (msg_select) select
|
482 |
|
|
msg_char <=
|
483 |
|
|
"00110000" when "00000", -- "0"; -- Hexadecimal characters
|
484 |
|
|
"00110001" when "00001", -- "1";
|
485 |
|
|
"00110010" when "00010", -- "2";
|
486 |
|
|
"00110011" when "00011", -- "3";
|
487 |
|
|
"00110100" when "00100", -- "4";
|
488 |
|
|
"00110101" when "00101", -- "5";
|
489 |
|
|
"00110110" when "00110", -- "6";
|
490 |
|
|
"00110111" when "00111", -- "7";
|
491 |
|
|
"00111000" when "01000", -- "8";
|
492 |
|
|
"00111001" when "01001", -- "9";
|
493 |
|
|
"01000001" when "01010", -- "A"; -- Address error indication
|
494 |
|
|
"01000010" when "01011", -- "B";
|
495 |
|
|
"01000011" when "01100", -- "C"; -- Command error indication
|
496 |
|
|
"01000100" when "01101", -- "D"; -- Data error indication
|
497 |
|
|
"01000101" when "01110", -- "E";
|
498 |
|
|
"01000110" when "01111", -- "F";
|
499 |
|
|
"00100000" when "10000", -- " "; -- Space
|
500 |
|
|
"00111010" when "10001", -- ":"; -- Colon
|
501 |
|
|
"00100000" when "10010", -- " "; -- Space
|
502 |
|
|
"00111111" when "10011", -- "?"; -- Parse error indication
|
503 |
|
|
"00100001" when "10100", -- "!"; -- ack_i/err_i error indication
|
504 |
|
|
"01001111" when "10101", -- "O"; -- "All is well" message
|
505 |
|
|
"01001011" when "10110", -- "K";
|
506 |
|
|
"00001101" when "10111", -- Carriage Return
|
507 |
|
|
"00001010" when "11000", -- Line Feed
|
508 |
|
|
"00101101" when "11001", -- "-"; -- Command Prompt
|
509 |
|
|
"00111110" when "11010", -- ">";
|
510 |
|
|
"00100000" when "11011", -- " ";
|
511 |
|
|
"01010001" when "11100", -- "Q"; -- Quantity error indication
|
512 |
|
|
"01011000" when others; -- "X";
|
513 |
|
|
|
514 |
|
|
-- This is state machine m1. It handles receiving the command line, including
|
515 |
|
|
-- backspaces, and prints error/response messages. It also parses and
|
516 |
|
|
-- executes the commands.
|
517 |
|
|
|
518 |
|
|
-- State register
|
519 |
|
|
fsm_proc : process(sys_clk, sys_rst_n)
|
520 |
|
|
|
521 |
|
|
procedure exec_prep is
|
522 |
|
|
begin
|
523 |
|
|
if (adr_offset=qty_sr) then
|
524 |
|
|
msg_pointer <= "10101"; -- Address of message
|
525 |
|
|
fsm_state <= SEND_OK;
|
526 |
|
|
else
|
527 |
|
|
watchdog_timer_count <= (others=>'0'); -- Reset the timer.
|
528 |
|
|
fsm_state <= EXECUTE;
|
529 |
|
|
end if;
|
530 |
|
|
end exec_prep;
|
531 |
|
|
|
532 |
|
|
begin
|
533 |
|
|
if (sys_rst_n='0') then -- asynchronous reset
|
534 |
|
|
rst_o <= '0';
|
535 |
|
|
fsm_state <= IDLE;
|
536 |
|
|
command <= INIT;
|
537 |
|
|
msg_pointer <= (others=>'0');
|
538 |
|
|
cmd_ptr <= (others=>'0');
|
539 |
|
|
adr_offset <= (others=>'0');
|
540 |
|
|
adr_freeze <= '0';
|
541 |
|
|
adr_sr <= (others=>'0');
|
542 |
|
|
dat_sr <= (others=>'0');
|
543 |
|
|
qty_sr <= to_unsigned(1,qty_sr'length); -- Set qty = 1 default.
|
544 |
|
|
display_field_count <= (others=>'0');
|
545 |
|
|
display_adr_digit_count <= (others=>'0');
|
546 |
|
|
display_dat_digit_count <= (others=>'0');
|
547 |
|
|
watchdog_timer_count <= (others=>'0');
|
548 |
|
|
display_adr_sr <= (others=>'0');
|
549 |
|
|
cmd_done_o <= '0';
|
550 |
|
|
comment_area <= '0';
|
551 |
|
|
elsif (sys_clk'event and sys_clk='1') then
|
552 |
|
|
if (sys_clk_en='1') then
|
553 |
|
|
|
554 |
|
|
-- Handle the Watchdog timer
|
555 |
|
|
if (watchdog_timer_done='0') then
|
556 |
|
|
watchdog_timer_count <= watchdog_timer_count+1;
|
557 |
|
|
end if;
|
558 |
|
|
|
559 |
|
|
-- Default values for outputs. The individual states can override these.
|
560 |
|
|
rst_o <= '0';
|
561 |
|
|
cmd_done_o <= '0';
|
562 |
|
|
|
563 |
|
|
case (fsm_state) is
|
564 |
|
|
|
565 |
|
|
when IDLE =>
|
566 |
|
|
msg_pointer <= (others=>'0');
|
567 |
|
|
fsm_state <= SEND_WELCOME_STRING;
|
568 |
|
|
|
569 |
|
|
when SEND_WELCOME_STRING =>
|
570 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
571 |
|
|
if (msg_pointer=15) then -- Send initial string ("0123456789ABCDEF")
|
572 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
573 |
|
|
fsm_state <= SEND_PROMPT;
|
574 |
|
|
else
|
575 |
|
|
msg_pointer <= msg_pointer+1;
|
576 |
|
|
end if;
|
577 |
|
|
end if;
|
578 |
|
|
|
579 |
|
|
when SEND_OK =>
|
580 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
581 |
|
|
if (msg_pointer=22) then -- Send 2 characters...
|
582 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
583 |
|
|
fsm_state <= SEND_PROMPT;
|
584 |
|
|
else
|
585 |
|
|
msg_pointer <= msg_pointer+1;
|
586 |
|
|
end if;
|
587 |
|
|
end if;
|
588 |
|
|
|
589 |
|
|
when SEND_PROMPT =>
|
590 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
591 |
|
|
if (msg_pointer=27) then -- Send 5 characters...
|
592 |
|
|
cmd_ptr <= (others=>'0');
|
593 |
|
|
cmd_done_o <= '1';
|
594 |
|
|
fsm_state <= CHECK_NEW_CHAR;
|
595 |
|
|
else
|
596 |
|
|
msg_pointer <= msg_pointer+1;
|
597 |
|
|
end if;
|
598 |
|
|
end if;
|
599 |
|
|
|
600 |
|
|
-- This state always leads to activating the parser...
|
601 |
|
|
when SEND_CRLF =>
|
602 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
603 |
|
|
if (msg_pointer=24) then -- Send 2 characters...
|
604 |
|
|
cmd_ptr <= (others=>'0');
|
605 |
|
|
fsm_state <= SCAN_CMD;
|
606 |
|
|
else
|
607 |
|
|
msg_pointer <= msg_pointer+1;
|
608 |
|
|
end if;
|
609 |
|
|
end if;
|
610 |
|
|
|
611 |
|
|
when CHECK_NEW_CHAR =>
|
612 |
|
|
if (cmd_we_i='1') then
|
613 |
|
|
if (cmd_char_i=BACKSPACE_CHAR) then
|
614 |
|
|
cmd_ptr <= cmd_ptr-1; -- This effectively eliminates the last char
|
615 |
|
|
elsif (comment_area='0' and cmd_char_i=ENTER_CHAR) or (cmd_ptr=CMD_BUFFER_SIZE-1) then
|
616 |
|
|
if (cmd_char_i=ENTER_CHAR) then
|
617 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
618 |
|
|
fsm_state <= SEND_CRLF;
|
619 |
|
|
end if;
|
620 |
|
|
if (cmd_ptr=CMD_BUFFER_SIZE-1) then
|
621 |
|
|
msg_pointer <= "10111"; -- Address of the message.
|
622 |
|
|
cmd_ptr <= (others=>'0');
|
623 |
|
|
fsm_state <= PARSE_ERR_INDICATOR_CRLF;
|
624 |
|
|
end if;
|
625 |
|
|
elsif (cmd_char_i=COMMENT_CHAR) then
|
626 |
|
|
comment_area <= '1'; -- Activate comment area, which stores characters, but does not advance cmd_ptr.
|
627 |
|
|
elsif (comment_area='0') then
|
628 |
|
|
cmd_ptr <= cmd_ptr+1;
|
629 |
|
|
end if;
|
630 |
|
|
-- Deactivate comment area at end of line
|
631 |
|
|
if (comment_area='1' and cmd_char_i=ENTER_CHAR) then
|
632 |
|
|
comment_area <= '0';
|
633 |
|
|
-- Check if a valid command might have preceded the comment
|
634 |
|
|
if (cmd_ptr>1) then
|
635 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
636 |
|
|
fsm_state <= SEND_CRLF;
|
637 |
|
|
else
|
638 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
639 |
|
|
fsm_state <= SEND_PROMPT;
|
640 |
|
|
end if;
|
641 |
|
|
end if;
|
642 |
|
|
end if;
|
643 |
|
|
|
644 |
|
|
when BG_ERR_INDICATOR =>
|
645 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
646 |
|
|
msg_pointer <= "10100"; -- Address of the error message
|
647 |
|
|
fsm_state <= ERR_INDICATOR;
|
648 |
|
|
end if;
|
649 |
|
|
|
650 |
|
|
-- This state is used when the line is too long...
|
651 |
|
|
when PARSE_ERR_INDICATOR_CRLF =>
|
652 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
653 |
|
|
if (msg_pointer=24) then -- Send 2 characters...
|
654 |
|
|
msg_pointer <= "10011"; -- Address of the message.
|
655 |
|
|
fsm_state <= ERR_INDICATOR;
|
656 |
|
|
else
|
657 |
|
|
msg_pointer <= msg_pointer+1;
|
658 |
|
|
end if;
|
659 |
|
|
end if;
|
660 |
|
|
|
661 |
|
|
when ERR_INDICATOR =>
|
662 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
663 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
664 |
|
|
fsm_state <= SEND_PROMPT;
|
665 |
|
|
end if;
|
666 |
|
|
|
667 |
|
|
when SEND_QUESTION =>
|
668 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
669 |
|
|
msg_pointer <= "10011"; -- Address of the message.
|
670 |
|
|
fsm_state <= ERR_INDICATOR;
|
671 |
|
|
end if;
|
672 |
|
|
|
673 |
|
|
-- The following states are for parsing and executing the command.
|
674 |
|
|
|
675 |
|
|
-- This state takes care of leading whitespace before the command
|
676 |
|
|
when SCAN_CMD =>
|
677 |
|
|
cmd_ptr <= cmd_ptr+1;
|
678 |
|
|
adr_offset <= (others=>'0');
|
679 |
|
|
case (lc_cmd_char) is
|
680 |
|
|
when "01110010" => -- "r"
|
681 |
|
|
command <= READ;
|
682 |
|
|
fsm_state <= CHECK_SUFFICES;
|
683 |
|
|
when "01110111" => -- "w"
|
684 |
|
|
command <= WRITE;
|
685 |
|
|
qty_sr <= (others=>'1'); -- Limit writes to the max. qty...
|
686 |
|
|
fsm_state <= CHECK_SUFFICES;
|
687 |
|
|
when "01101001" => -- "i"
|
688 |
|
|
command <= INIT;
|
689 |
|
|
qty_sr <= (others=>'0');
|
690 |
|
|
rst_o <= '1'; -- Actually do this one right now!!
|
691 |
|
|
fsm_state <= START_EXECUTION;
|
692 |
|
|
when "01100110" => -- "f"
|
693 |
|
|
command <= FILL;
|
694 |
|
|
fsm_state <= CHECK_SUFFICES;
|
695 |
|
|
when others =>
|
696 |
|
|
if (char_is_whitespace='0') then
|
697 |
|
|
msg_pointer <= "01100"; -- Address of message
|
698 |
|
|
fsm_state <= SEND_QUESTION;
|
699 |
|
|
end if;
|
700 |
|
|
end case;
|
701 |
|
|
|
702 |
|
|
-- This state cleverly detects command "suffix" modifiers, such
|
703 |
|
|
-- as the '0' modifier, which causes the address to remain frozen.
|
704 |
|
|
-- Invalid or unimplemented suffix modifiers elicit the "C?" response.
|
705 |
|
|
when CHECK_SUFFICES => -- Should that read "check suffixes" Hmmm...
|
706 |
|
|
if (cmd_char="00110000") then -- '0' suffix
|
707 |
|
|
cmd_ptr <= cmd_ptr+1;
|
708 |
|
|
adr_freeze <= '1';
|
709 |
|
|
fsm_state <= SCAN_ADR_WHITESPACE;
|
710 |
|
|
elsif (cmd_char=ENTER_CHAR) then
|
711 |
|
|
fsm_state <= START_EXECUTION; -- Using last values
|
712 |
|
|
elsif (char_is_whitespace='1') then
|
713 |
|
|
adr_freeze <= '0';
|
714 |
|
|
fsm_state <= SCAN_ADR_WHITESPACE;
|
715 |
|
|
else
|
716 |
|
|
msg_pointer <= "01100"; -- Address of message
|
717 |
|
|
fsm_state <= SEND_QUESTION;
|
718 |
|
|
end if;
|
719 |
|
|
|
720 |
|
|
|
721 |
|
|
-- The only way to determine the end of a valid field is to find
|
722 |
|
|
-- whitespace. Therefore, char_is_whitespace must be used as an exit
|
723 |
|
|
-- condition from the "get_xxx_field" states. So, this state is used to
|
724 |
|
|
-- scan through any leading whitespace prior to the first field.
|
725 |
|
|
when SCAN_ADR_WHITESPACE =>
|
726 |
|
|
if (char_is_whitespace='1') then
|
727 |
|
|
cmd_ptr <= cmd_ptr+1;
|
728 |
|
|
elsif (cmd_char=ENTER_CHAR) then
|
729 |
|
|
fsm_state <= START_EXECUTION; -- Using last values
|
730 |
|
|
else
|
731 |
|
|
fsm_state <= GET_ADR_FIELD;
|
732 |
|
|
adr_sr <= (others=>'0');
|
733 |
|
|
end if;
|
734 |
|
|
|
735 |
|
|
when GET_ADR_FIELD =>
|
736 |
|
|
if (char_is_hex='1') then
|
737 |
|
|
adr_sr <= adr_sr(4*(ADR_DIGITS-1)-1 downto 0) & hex_digit;
|
738 |
|
|
cmd_ptr <= cmd_ptr+1;
|
739 |
|
|
elsif (char_is_whitespace='1') then -- Normal exit
|
740 |
|
|
fsm_state <= SCAN_DAT_WHITESPACE;
|
741 |
|
|
elsif (cmd_char=ENTER_CHAR and command=READ) then
|
742 |
|
|
fsm_state <= START_EXECUTION; -- Using last values
|
743 |
|
|
else
|
744 |
|
|
msg_pointer <= "01010"; -- Address of message
|
745 |
|
|
fsm_state <= SEND_QUESTION;
|
746 |
|
|
end if;
|
747 |
|
|
|
748 |
|
|
when SCAN_DAT_WHITESPACE =>
|
749 |
|
|
-- There is no DAT field for reads, so skip it.
|
750 |
|
|
if (command=READ) then
|
751 |
|
|
fsm_state <= SCAN_QTY_WHITESPACE;
|
752 |
|
|
elsif (char_is_whitespace='1') then
|
753 |
|
|
cmd_ptr <= cmd_ptr+1;
|
754 |
|
|
elsif (cmd_char=ENTER_CHAR) then
|
755 |
|
|
if (command=WRITE) then -- Writing data values done, finish.
|
756 |
|
|
msg_pointer <= "10101"; -- Address of message
|
757 |
|
|
fsm_state <= SEND_OK;
|
758 |
|
|
else
|
759 |
|
|
fsm_state <= START_EXECUTION; -- Using last DATA & QTY values
|
760 |
|
|
end if;
|
761 |
|
|
else
|
762 |
|
|
fsm_state <= GET_DAT_FIELD;
|
763 |
|
|
dat_sr <= (others=>'0');
|
764 |
|
|
end if;
|
765 |
|
|
|
766 |
|
|
when GET_DAT_FIELD =>
|
767 |
|
|
if (char_is_hex='1') then
|
768 |
|
|
dat_sr <= dat_sr(4*(DAT_DIGITS-1)-1 downto 0) & hex_digit;
|
769 |
|
|
cmd_ptr <= cmd_ptr+1;
|
770 |
|
|
elsif (char_is_whitespace='1') then -- Normal exit
|
771 |
|
|
if (command=WRITE) then
|
772 |
|
|
fsm_state <= START_EXECUTION;
|
773 |
|
|
else
|
774 |
|
|
fsm_state <= SCAN_QTY_WHITESPACE;
|
775 |
|
|
end if;
|
776 |
|
|
elsif (cmd_char=ENTER_CHAR) then
|
777 |
|
|
fsm_state <= START_EXECUTION;
|
778 |
|
|
else
|
779 |
|
|
msg_pointer <= "01101"; -- Address of message
|
780 |
|
|
fsm_state <= SEND_QUESTION;
|
781 |
|
|
end if;
|
782 |
|
|
|
783 |
|
|
when SCAN_QTY_WHITESPACE =>
|
784 |
|
|
if (char_is_whitespace='1') then
|
785 |
|
|
cmd_ptr <= cmd_ptr+1;
|
786 |
|
|
elsif (cmd_char=ENTER_CHAR) then
|
787 |
|
|
fsm_state <= START_EXECUTION; -- Using last values
|
788 |
|
|
else
|
789 |
|
|
fsm_state <= GET_QTY_FIELD;
|
790 |
|
|
qty_sr <= to_unsigned(0,qty_sr'length);
|
791 |
|
|
end if;
|
792 |
|
|
|
793 |
|
|
when GET_QTY_FIELD =>
|
794 |
|
|
if (char_is_hex='1') then
|
795 |
|
|
qty_sr <= qty_sr(4*(QTY_DIGITS-1)-1 downto 0) & hex_digit;
|
796 |
|
|
cmd_ptr <= cmd_ptr+1;
|
797 |
|
|
elsif (char_is_whitespace='1' or cmd_char=ENTER_CHAR) then -- Normal exit
|
798 |
|
|
fsm_state <= START_EXECUTION;
|
799 |
|
|
else
|
800 |
|
|
msg_pointer <= "11100"; -- Address of message
|
801 |
|
|
fsm_state <= SEND_QUESTION;
|
802 |
|
|
end if;
|
803 |
|
|
|
804 |
|
|
-- This state seeks to obtain master_bg_i, which grants the bus for use.
|
805 |
|
|
when START_EXECUTION =>
|
806 |
|
|
watchdog_timer_count <= (others=>'0'); -- Reset the timer.
|
807 |
|
|
display_adr_sr <= adr_ptr;
|
808 |
|
|
display_field_count <= (others=>'0');
|
809 |
|
|
if (master_bg_i='1') then -- skip REQUEST_BUS if it is already granted!
|
810 |
|
|
exec_prep;
|
811 |
|
|
else
|
812 |
|
|
fsm_state <= REQUEST_BUS;
|
813 |
|
|
end if;
|
814 |
|
|
|
815 |
|
|
when REQUEST_BUS =>
|
816 |
|
|
if (master_bg_i='1') then
|
817 |
|
|
exec_prep; -- resets watchdog, sends "OK" if done.
|
818 |
|
|
elsif (watchdog_timer_done='1') then
|
819 |
|
|
msg_pointer <= "01011"; -- Address of messsage
|
820 |
|
|
fsm_state <= BG_ERR_INDICATOR;
|
821 |
|
|
end if;
|
822 |
|
|
|
823 |
|
|
-- This single state does fill/write/read depending upon the value
|
824 |
|
|
-- contained in "command"!
|
825 |
|
|
when EXECUTE =>
|
826 |
|
|
if (watchdog_timer_done='1' or err_i='1') then
|
827 |
|
|
fsm_state <= BG_ERR_INDICATOR;
|
828 |
|
|
elsif (ack_i='1' and master_bg_i='1') then
|
829 |
|
|
case command is
|
830 |
|
|
when READ =>
|
831 |
|
|
dat_sr <= dat_i; -- Capture the read data
|
832 |
|
|
display_adr_sr <= adr_ptr;
|
833 |
|
|
fsm_state <= DISPLAY_PREP;
|
834 |
|
|
when WRITE =>
|
835 |
|
|
adr_offset <= adr_offset+1;
|
836 |
|
|
fsm_state <= SCAN_DAT_WHITESPACE; -- Continue to next data value
|
837 |
|
|
when FILL =>
|
838 |
|
|
adr_offset <= adr_offset+1;
|
839 |
|
|
fsm_state <= POST_FILL_CYCLE;
|
840 |
|
|
when others =>
|
841 |
|
|
fsm_state <= POST_FILL_CYCLE;
|
842 |
|
|
end case;
|
843 |
|
|
end if;
|
844 |
|
|
|
845 |
|
|
when POST_FILL_CYCLE =>
|
846 |
|
|
exec_prep; -- resets watchdog, sends "OK" if done.
|
847 |
|
|
|
848 |
|
|
when DISPLAY_PREP =>
|
849 |
|
|
adr_offset <= adr_offset+1;
|
850 |
|
|
if (display_field_count = 0) then -- Check to see if address display is needed yet.
|
851 |
|
|
msg_pointer <= '0' & display_adr_sr(4*ADR_DIGITS-1 downto 4*(ADR_DIGITS-1));
|
852 |
|
|
display_adr_digit_count <= (others=>'0');
|
853 |
|
|
display_adr_sr <= adr_ptr;
|
854 |
|
|
fsm_state <= DISPLAY_ADR; -- Leads to a new address line.
|
855 |
|
|
else
|
856 |
|
|
display_dat_digit_count <= (others=>'0');
|
857 |
|
|
msg_pointer <= '0' & dat_sr(4*DAT_DIGITS-1 downto 4*(DAT_DIGITS-1));
|
858 |
|
|
fsm_state <= DISPLAY_DAT;
|
859 |
|
|
end if;
|
860 |
|
|
|
861 |
|
|
when DISPLAY_ADR =>
|
862 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
863 |
|
|
if (display_adr_digit_count = ADR_DIGITS-1) then
|
864 |
|
|
msg_pointer <= "10000"; -- Address of the message
|
865 |
|
|
fsm_state <= DISPLAY_SEPARATOR;
|
866 |
|
|
else
|
867 |
|
|
display_adr_sr <= display_adr_sr(4*(ADR_DIGITS-1)-1 downto 0) & to_unsigned(0,4);
|
868 |
|
|
display_adr_digit_count <= display_adr_digit_count+1;
|
869 |
|
|
end if;
|
870 |
|
|
end if;
|
871 |
|
|
|
872 |
|
|
when DISPLAY_SEPARATOR =>
|
873 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
874 |
|
|
msg_pointer <= msg_pointer+1;
|
875 |
|
|
if (msg_pointer = 18) then -- Three characters
|
876 |
|
|
display_dat_digit_count <= (others=>'0');
|
877 |
|
|
msg_pointer <= '0' & dat_sr(4*DAT_DIGITS-1 downto 4*(DAT_DIGITS-1));
|
878 |
|
|
fsm_state <= DISPLAY_DAT;
|
879 |
|
|
end if;
|
880 |
|
|
end if;
|
881 |
|
|
|
882 |
|
|
when DISPLAY_DAT =>
|
883 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
884 |
|
|
if (
|
885 |
|
|
(display_dat_digit_count = DAT_DIGITS-1)
|
886 |
|
|
and (display_field_count = DISPLAY_FIELDS-1)
|
887 |
|
|
)
|
888 |
|
|
then
|
889 |
|
|
msg_pointer <= "10111"; -- Address of the message
|
890 |
|
|
fsm_state <= DISPLAY_CRLF;
|
891 |
|
|
display_field_count <= (others=>'0');
|
892 |
|
|
elsif (display_dat_digit_count = DAT_DIGITS-1) then
|
893 |
|
|
msg_pointer <= "10000"; -- Address of the message
|
894 |
|
|
fsm_state <= DISPLAY_SPACE;
|
895 |
|
|
display_field_count <= display_field_count+1;
|
896 |
|
|
else
|
897 |
|
|
dat_sr <= dat_sr(4*(DAT_DIGITS-1)-1 downto 0) & hex_digit;
|
898 |
|
|
display_dat_digit_count <= display_dat_digit_count+1;
|
899 |
|
|
end if;
|
900 |
|
|
end if;
|
901 |
|
|
|
902 |
|
|
when DISPLAY_SPACE =>
|
903 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
904 |
|
|
exec_prep; -- resets watchdog, sends "OK" if done.
|
905 |
|
|
end if;
|
906 |
|
|
|
907 |
|
|
when DISPLAY_CRLF =>
|
908 |
|
|
if (resp_cyc_l='1' and resp_ack_i='1') then
|
909 |
|
|
msg_pointer <= msg_pointer+1;
|
910 |
|
|
if (msg_pointer=24) then -- Two characters
|
911 |
|
|
exec_prep; -- resets watchdog, sends "OK" if done.
|
912 |
|
|
end if;
|
913 |
|
|
end if;
|
914 |
|
|
|
915 |
|
|
--when others =>
|
916 |
|
|
-- fsm_state <= IDLE;
|
917 |
|
|
end case;
|
918 |
|
|
|
919 |
|
|
end if; -- sys_clk_en
|
920 |
|
|
end if; -- sys_clk
|
921 |
|
|
end process;
|
922 |
|
|
|
923 |
|
|
-- Assert needed outputs during execution of bus cycles
|
924 |
|
|
master_br_o <= '1' when (fsm_state=REQUEST_BUS or fsm_state=EXECUTE) else '0';
|
925 |
|
|
we_l <= '1' when (fsm_state=EXECUTE and (command=WRITE or command=FILL)) else '0';
|
926 |
|
|
stb_l <= '1' when (fsm_state=EXECUTE) else '0';
|
927 |
|
|
|
928 |
|
|
|
929 |
|
|
-- This is the command buffer writing section
|
930 |
|
|
ram_proc : process(sys_clk,sys_rst_n)
|
931 |
|
|
variable i : natural;
|
932 |
|
|
begin
|
933 |
|
|
if (sys_rst_n='0') then
|
934 |
|
|
-- synthesis translate_off
|
935 |
|
|
-- The initialization of the command buffer is for convenience in simulation only.
|
936 |
|
|
-- It can be removed for synthesis.
|
937 |
|
|
for i in 0 to CMD_BUFFER_SIZE-1 loop
|
938 |
|
|
cmd_buffer(i) <= (others=>'0');
|
939 |
|
|
end loop;
|
940 |
|
|
-- synthesis translate_on
|
941 |
|
|
elsif (sys_clk'event and sys_clk='1') then
|
942 |
|
|
if (sys_clk_en='1') then
|
943 |
|
|
if (cmd_we_i='1' and fsm_state=CHECK_NEW_CHAR) then
|
944 |
|
|
cmd_buffer(to_integer(cmd_ptr)) <= cmd_char_i;
|
945 |
|
|
end if;
|
946 |
|
|
-- Latch the command pointer, for synchronous reads.
|
947 |
|
|
--rd_cmd_ptr <= cmd_ptr; -- Use this to infer BRAM.
|
948 |
|
|
end if;
|
949 |
|
|
end if;
|
950 |
|
|
end process;
|
951 |
|
|
|
952 |
|
|
-- This is the command buffer reading section
|
953 |
|
|
cmd_char <= cmd_buffer(to_integer(cmd_ptr)); -- Asynchronous read. Amazingly, this was the better option in XC2S200E...
|
954 |
|
|
--cmd_char <= cmd_buffer(to_integer(rd_cmd_ptr)); -- Synchronous read, use this to infer BRAM.
|
955 |
|
|
lc_cmd_char <= (cmd_char or "00100000"); -- lowercase
|
956 |
|
|
|
957 |
|
|
-- These assigments are for detecting whether the cmd_char is
|
958 |
|
|
-- anything of special interest.
|
959 |
|
|
char_is_whitespace <= '1' when ((cmd_char=16#20#) -- space
|
960 |
|
|
or (cmd_char=16#09#) -- tab
|
961 |
|
|
or (cmd_char=16#0A#) -- line feed
|
962 |
|
|
) else '0';
|
963 |
|
|
char_is_num <= '1' when ((cmd_char>=16#30#) and (cmd_char<=16#39#)) else '0';
|
964 |
|
|
char_is_a_f <= '1' when ((lc_cmd_char>=16#61#) and (lc_cmd_char<=16#66#)) else '0';
|
965 |
|
|
char_is_hex <= char_is_num or char_is_a_f;
|
966 |
|
|
|
967 |
|
|
hex_digit <= cmd_char(3 downto 0) when char_is_num='1' else (cmd_char(3 downto 0)+"1001");
|
968 |
|
|
|
969 |
|
|
watchdog_timer_done <= '1' when (watchdog_timer_count=WATCHDOG_VALUE) else '0';
|
970 |
|
|
|
971 |
|
|
end beh;
|
972 |
|
|
|
973 |
|
|
|
974 |
|
|
---------------------------------------------------------------------------------------
|
975 |
|
|
--
|
976 |
|
|
-- Author: John Clayton
|
977 |
|
|
-- Date : Nov. 20, 2009
|
978 |
|
|
-- Update: 11/20/09 copied this file from rs232_syscon.v Began translating.
|
979 |
|
|
-- 10/04/11 Removed msg_offset+msg_base adder, in a bid to
|
980 |
|
|
-- increase max operating speed of this module.
|
981 |
|
|
-- Combined CMD_ERR_INDICATOR, ADR_ERR_INDICATOR,
|
982 |
|
|
-- DAT_ERR_INDICATOR, and QTY_ERR_INDICATOR
|
983 |
|
|
-- into a single state : SEND_QUESTION
|
984 |
|
|
-- Combined ACK_ERR_INDICATOR and PARSE_ERR_INDICATOR
|
985 |
|
|
-- into a single state : ERR_INDICATOR
|
986 |
|
|
-- 08/03/13 Removed rs232_tx_active_o, since it appears to be a
|
987 |
|
|
-- vestigial relic of a time long ago when the echoing of
|
988 |
|
|
-- command characters was done through the UART, and not
|
989 |
|
|
-- directly as it is now. It was staying high all the
|
990 |
|
|
-- time except for brief pulses low during generated
|
991 |
|
|
-- responses... which is not useful.
|
992 |
|
|
-- 08/03/13 Added "cmd_done_o" output pulse, which helps outside
|
993 |
|
|
-- serial command generators know when to begin generating
|
994 |
|
|
-- the next command. Removed the "rs232_" prefix from
|
995 |
|
|
-- signal names, since the signals really aren't at RS232
|
996 |
|
|
-- levels.
|
997 |
|
|
-- 08/03/13 Changed module and packet name to replace "rs232_"
|
998 |
|
|
-- with "async_"
|
999 |
|
|
-- 08/07/13 Added logic to include a "single line" type of comment
|
1000 |
|
|
-- which allows initialization strings and messages to
|
1001 |
|
|
-- include comments, which are echoed back over the
|
1002 |
|
|
-- interface for the user to perhaps see.
|
1003 |
|
|
--
|
1004 |
|
|
-- Description
|
1005 |
|
|
---------------------------------------------------------------------------------------
|
1006 |
|
|
-- This module takes an "ascii_syscon" unit and adds an asynchronous serial
|
1007 |
|
|
-- interface to it.
|
1008 |
|
|
--
|
1009 |
|
|
-- For details of command and response syntax, please refer to the ascii_syscon
|
1010 |
|
|
-- description.
|
1011 |
|
|
--
|
1012 |
|
|
---------------------------------------------------------------------------------------
|
1013 |
|
|
|
1014 |
|
|
library IEEE;
|
1015 |
|
|
use IEEE.STD_LOGIC_1164.ALL;
|
1016 |
|
|
use IEEE.NUMERIC_STD.ALL;
|
1017 |
|
|
use IEEE.MATH_REAL.ALL;
|
1018 |
|
|
|
1019 |
|
|
library work;
|
1020 |
|
|
use work.convert_pack.all;
|
1021 |
|
|
use work.uart_sqclk_pack.all;
|
1022 |
|
|
use work.async_syscon_pack.all;
|
1023 |
|
|
|
1024 |
|
|
entity async_syscon is
|
1025 |
|
|
generic (
|
1026 |
|
|
ECHO_COMMANDS : natural := 1; -- set nonzero to echo back command characters
|
1027 |
|
|
ADR_DIGITS : natural := 4; -- # of hex digits for address
|
1028 |
|
|
DAT_DIGITS : natural := 4; -- # of hex digits for data
|
1029 |
|
|
QTY_DIGITS : natural := 2; -- # of hex digits for quantity
|
1030 |
|
|
CMD_BUFFER_SIZE : natural := 32; -- # of chars in the command buffer
|
1031 |
|
|
WATCHDOG_VALUE : natural := 200; -- # of sys_clks before ack is expected
|
1032 |
|
|
DISPLAY_FIELDS : natural := 8 -- # of fields/line
|
1033 |
|
|
);
|
1034 |
|
|
port (
|
1035 |
|
|
|
1036 |
|
|
sys_rst_n : in std_logic;
|
1037 |
|
|
sys_clk : in std_logic;
|
1038 |
|
|
sys_clk_en : in std_logic;
|
1039 |
|
|
|
1040 |
|
|
-- rate and parity
|
1041 |
|
|
parity_i : in unsigned(1 downto 0); -- 0=none, 1=even, 2=odd
|
1042 |
|
|
baud_clk_i : in std_logic; -- At 1x the desired baud rate, can be squarewave or pulses.
|
1043 |
|
|
baud_lock_i : in std_logic; -- '1' Indicates baud clock is stable and ready.
|
1044 |
|
|
|
1045 |
|
|
-- Serial IO
|
1046 |
|
|
cmd_i : in std_logic;
|
1047 |
|
|
resp_o : out std_logic;
|
1048 |
|
|
cmd_done_o : out std_logic;
|
1049 |
|
|
|
1050 |
|
|
-- Master Bus IO
|
1051 |
|
|
master_bg_i : in std_logic;
|
1052 |
|
|
master_ack_o : out std_logic;
|
1053 |
|
|
master_adr_i : in unsigned(4*ADR_DIGITS-1 downto 0);
|
1054 |
|
|
master_dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
|
1055 |
|
|
master_dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
|
1056 |
|
|
master_stb_i : in std_logic;
|
1057 |
|
|
master_we_i : in std_logic;
|
1058 |
|
|
master_br_o : out std_logic;
|
1059 |
|
|
|
1060 |
|
|
-- System Bus IO
|
1061 |
|
|
ack_i : in std_logic;
|
1062 |
|
|
err_i : in std_logic;
|
1063 |
|
|
dat_i : in unsigned(4*DAT_DIGITS-1 downto 0);
|
1064 |
|
|
dat_o : out unsigned(4*DAT_DIGITS-1 downto 0);
|
1065 |
|
|
rst_o : out std_logic;
|
1066 |
|
|
stb_o : out std_logic;
|
1067 |
|
|
cyc_o : out std_logic;
|
1068 |
|
|
adr_o : out unsigned(4*ADR_DIGITS-1 downto 0);
|
1069 |
|
|
we_o : out std_logic
|
1070 |
|
|
);
|
1071 |
|
|
end async_syscon;
|
1072 |
|
|
|
1073 |
|
|
architecture beh of async_syscon is
|
1074 |
|
|
|
1075 |
|
|
-- Constants
|
1076 |
|
|
constant ENTER_CHAR : unsigned := "00001101";
|
1077 |
|
|
|
1078 |
|
|
-- Signals
|
1079 |
|
|
-- For ascii_syscon
|
1080 |
|
|
signal cmd_char : unsigned(7 downto 0);
|
1081 |
|
|
signal cmd_we_uart : std_logic;
|
1082 |
|
|
signal cmd_we_wait : std_logic;
|
1083 |
|
|
signal cmd_rx_done : std_logic;
|
1084 |
|
|
signal cmd_we : std_logic;
|
1085 |
|
|
signal cmd_ack : std_logic;
|
1086 |
|
|
signal cmd_echo : std_logic;
|
1087 |
|
|
signal resp_char : unsigned(7 downto 0);
|
1088 |
|
|
signal resp_cyc : std_logic;
|
1089 |
|
|
signal resp_cyc_r1 : std_logic;
|
1090 |
|
|
signal resp_cyc_uart : std_logic;
|
1091 |
|
|
signal resp_ack_uart : std_logic;
|
1092 |
|
|
signal resp_ack_uart_r1 : std_logic;
|
1093 |
|
|
signal resp_ack : std_logic;
|
1094 |
|
|
|
1095 |
|
|
-- For the serial interface
|
1096 |
|
|
signal async_rx_error : unsigned(1 downto 0);
|
1097 |
|
|
signal async_rx_restart : std_logic;
|
1098 |
|
|
signal resp_l : std_logic;
|
1099 |
|
|
|
1100 |
|
|
----------------------------------------------------------------------------
|
1101 |
|
|
-- Component Declarations
|
1102 |
|
|
----------------------------------------------------------------------------
|
1103 |
|
|
|
1104 |
|
|
----------------------------------------------------------------------------
|
1105 |
|
|
begin
|
1106 |
|
|
|
1107 |
|
|
----------------------------------------------------------------------------
|
1108 |
|
|
-- Instantiations
|
1109 |
|
|
----------------------------------------------------------------------------
|
1110 |
|
|
|
1111 |
|
|
uart1 : uart_sqclk
|
1112 |
|
|
port map (
|
1113 |
|
|
|
1114 |
|
|
sys_rst_n => sys_rst_n,
|
1115 |
|
|
sys_clk => sys_clk,
|
1116 |
|
|
sys_clk_en => sys_clk_en,
|
1117 |
|
|
|
1118 |
|
|
-- rate and parity
|
1119 |
|
|
parity_i => parity_i,
|
1120 |
|
|
rate_clk_i => baud_clk_i,
|
1121 |
|
|
|
1122 |
|
|
-- serial I/O
|
1123 |
|
|
tx_stream => resp_l,
|
1124 |
|
|
rx_stream => cmd_i,
|
1125 |
|
|
|
1126 |
|
|
--control and status
|
1127 |
|
|
tx_wr_i => resp_cyc_uart,
|
1128 |
|
|
tx_dat_i => resp_char,
|
1129 |
|
|
tx_done_o => resp_ack_uart,
|
1130 |
|
|
rx_restart_i => async_rx_restart, -- High clears error flags, clears rx_done_o
|
1131 |
|
|
rx_dat_o => cmd_char,
|
1132 |
|
|
rx_wr_o => cmd_we_uart, -- High pulse means store rx_dat_o.
|
1133 |
|
|
rx_done_o => cmd_rx_done, -- Remains high after receive, until clk edge with rx_restart_i=1
|
1134 |
|
|
frame_err_o => async_rx_error(0), -- High = error. Reset when rx_restart_i asserted.
|
1135 |
|
|
parity_err_o => async_rx_error(1) -- High = error. Reset when rx_restart_i asserted.
|
1136 |
|
|
);
|
1137 |
|
|
|
1138 |
|
|
syscon1 : ascii_syscon
|
1139 |
|
|
generic map(
|
1140 |
|
|
ADR_DIGITS => ADR_DIGITS, -- # of hex digits for address
|
1141 |
|
|
DAT_DIGITS => DAT_DIGITS, -- # of hex digits for data
|
1142 |
|
|
QTY_DIGITS => QTY_DIGITS, -- # of hex digits for quantity
|
1143 |
|
|
CMD_BUFFER_SIZE => CMD_BUFFER_SIZE, -- # of chars in the command buffer
|
1144 |
|
|
WATCHDOG_VALUE => WATCHDOG_VALUE, -- # of sys_clks before ack is expected
|
1145 |
|
|
DISPLAY_FIELDS => DISPLAY_FIELDS -- # of fields/line
|
1146 |
|
|
)
|
1147 |
|
|
port map(
|
1148 |
|
|
|
1149 |
|
|
sys_rst_n => sys_rst_n,
|
1150 |
|
|
sys_clk => sys_clk,
|
1151 |
|
|
sys_clk_en => sys_clk_en,
|
1152 |
|
|
|
1153 |
|
|
-- Parallel ASCII I/O
|
1154 |
|
|
cmd_char_i => cmd_char,
|
1155 |
|
|
cmd_we_i => cmd_we,
|
1156 |
|
|
cmd_ack_o => cmd_ack,
|
1157 |
|
|
cmd_echo_o => cmd_echo,
|
1158 |
|
|
resp_char_o => resp_char,
|
1159 |
|
|
resp_cyc_o => resp_cyc,
|
1160 |
|
|
resp_ack_i => resp_ack,
|
1161 |
|
|
cmd_done_o => cmd_done_o,
|
1162 |
|
|
|
1163 |
|
|
-- Master Bus IO
|
1164 |
|
|
master_bg_i => master_bg_i,
|
1165 |
|
|
master_ack_o => master_ack_o,
|
1166 |
|
|
master_adr_i => master_adr_i,
|
1167 |
|
|
master_dat_i => master_dat_i,
|
1168 |
|
|
master_dat_o => master_dat_o,
|
1169 |
|
|
master_stb_i => master_stb_i,
|
1170 |
|
|
master_we_i => master_we_i,
|
1171 |
|
|
master_br_o => master_br_o,
|
1172 |
|
|
|
1173 |
|
|
-- System Bus IO
|
1174 |
|
|
ack_i => ack_i,
|
1175 |
|
|
err_i => err_i,
|
1176 |
|
|
dat_i => dat_i,
|
1177 |
|
|
dat_o => dat_o,
|
1178 |
|
|
rst_o => rst_o,
|
1179 |
|
|
stb_o => stb_o,
|
1180 |
|
|
cyc_o => cyc_o,
|
1181 |
|
|
adr_o => adr_o,
|
1182 |
|
|
we_o => we_o
|
1183 |
|
|
);
|
1184 |
|
|
|
1185 |
|
|
----------------------------------------------------------------------------
|
1186 |
|
|
-- Module code
|
1187 |
|
|
----------------------------------------------------------------------------
|
1188 |
|
|
|
1189 |
|
|
async_rx_restart <= async_rx_error(0) or async_rx_error(1) or cmd_ack;
|
1190 |
|
|
resp_o <= resp_l when cmd_echo='0' else
|
1191 |
|
|
cmd_i when ECHO_COMMANDS/=0 else
|
1192 |
|
|
'1';
|
1193 |
|
|
|
1194 |
|
|
-- Detect rising edge of resp_ack_uart
|
1195 |
|
|
resp_ack_proc: Process(sys_rst_n,sys_clk)
|
1196 |
|
|
begin
|
1197 |
|
|
if (sys_rst_n = '0') then
|
1198 |
|
|
resp_ack_uart_r1 <= '1';
|
1199 |
|
|
elsif (sys_clk'event AND sys_clk='1') then
|
1200 |
|
|
if (sys_clk_en='1') then
|
1201 |
|
|
resp_ack_uart_r1 <= resp_ack_uart;
|
1202 |
|
|
end if;
|
1203 |
|
|
end if; -- sys_clk
|
1204 |
|
|
end process;
|
1205 |
|
|
resp_ack <= '1' when resp_ack_uart='1' and resp_ack_uart_r1='0' else '0';
|
1206 |
|
|
|
1207 |
|
|
-- Detect rising edge of resp_cyc
|
1208 |
|
|
resp_cyc_proc: Process(sys_rst_n,sys_clk)
|
1209 |
|
|
begin
|
1210 |
|
|
if (sys_rst_n = '0') then
|
1211 |
|
|
resp_cyc_r1 <= '1';
|
1212 |
|
|
elsif (sys_clk'event AND sys_clk='1') then
|
1213 |
|
|
if (sys_clk_en='1') then
|
1214 |
|
|
resp_cyc_r1 <= resp_cyc;
|
1215 |
|
|
end if;
|
1216 |
|
|
end if; -- sys_clk
|
1217 |
|
|
end process;
|
1218 |
|
|
resp_cyc_uart <= '1' when resp_cyc='1' and resp_cyc_r1='0' else '0';
|
1219 |
|
|
|
1220 |
|
|
-- Create a valid command write enable, that waits until the final echoed
|
1221 |
|
|
-- character (CHAR_ENTER) is done being transmitted
|
1222 |
|
|
cmd_we_proc: Process(sys_rst_n,sys_clk)
|
1223 |
|
|
begin
|
1224 |
|
|
if (sys_rst_n = '0') then
|
1225 |
|
|
cmd_we_wait <= '0';
|
1226 |
|
|
elsif (sys_clk'event AND sys_clk='1') then
|
1227 |
|
|
if (sys_clk_en='1') then
|
1228 |
|
|
if (cmd_we_uart='1' and cmd_we_wait='0') then
|
1229 |
|
|
cmd_we_wait <= '1';
|
1230 |
|
|
end if;
|
1231 |
|
|
if (cmd_we_wait='1') then
|
1232 |
|
|
if (cmd_rx_done='1') then
|
1233 |
|
|
cmd_we_wait <= '0';
|
1234 |
|
|
end if;
|
1235 |
|
|
end if;
|
1236 |
|
|
end if;
|
1237 |
|
|
end if; -- sys_clk
|
1238 |
|
|
end process;
|
1239 |
|
|
|
1240 |
|
|
cmd_we <= cmd_we_uart when baud_lock_i='1' and cmd_char/=ENTER_CHAR else
|
1241 |
|
|
'1' when baud_lock_i='1' and cmd_char=ENTER_CHAR and cmd_we_wait='1' and cmd_rx_done='1' else
|
1242 |
|
|
'0';
|
1243 |
|
|
|
1244 |
|
|
end beh;
|
1245 |
|
|
|
1246 |
|
|
|