Subversion Repositories wb4pb

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;; This sourcecode is released under BSD license.

;; Please see http://www.opensource.org/licenses/bsd-license.php for details!

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;;

;; Copyright (c) 2010, Stefan Fischer 

;; All rights reserved.

;;

;; Redistribution and use in source and binary forms, with or without

;; modification, are permitted provided that the following conditions are met:

;;

;;  * Redistributions of source code must retain the above copyright notice,

;;    this list of conditions and the following disclaimer.

;;  * Redistributions in binary form must reproduce the above copyright notice,

;;    this list of conditions and the following disclaimer in the documentation

;;    and/or other materials provided with the distribution.

;;

;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

;; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

;; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

;; ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

;; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

;; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

;; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

;; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

;; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

;; POSSIBILITY OF SUCH DAMAGE.

;;

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;; filename: pbwbuart.psm

;; description: uart example, demonstrating access to wishbone peripherals

;; todo4user: modify main program and uart code as needed, i. e. non-blocking

;;            read and write transactions or data burst transfers

;; version: 0.0.0

;; changelog: - 0.0.0, initial release

;;            - ...

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; wishbone variables

NAMEREG sF , wb_addr

NAMEREG sE , wb_data ; also used as tmp-reg for status polling

; uart variables

NAMEREG sD , uart_data

ADDRESS 000

; main entry point

;;;;;;;;;;;;;;;;;;

DISABLE INTERRUPT

CALL uart_init

; obligatory "Hello World!" message

; new line

LOAD uart_data , ASCII_CR_CHAR

CALL uart_wr_byte

LOAD uart_data , ASCII_LF_CHAR

CALL uart_wr_byte

; H

LOAD uart_data , ASCII_H_UC

CALL uart_wr_byte

; e

LOAD uart_data , ASCII_E_LC

CALL uart_wr_byte

; l

LOAD uart_data , ASCII_L_LC

CALL uart_wr_byte

; l

LOAD uart_data , ASCII_L_LC

CALL uart_wr_byte

; o

LOAD uart_data , ASCII_O_LC

CALL uart_wr_byte

; space

LOAD uart_data , ASCII_SP_CHAR

CALL uart_wr_byte

; W

LOAD uart_data , ASCII_W_UC

CALL uart_wr_byte

; o

LOAD uart_data , ASCII_O_LC

CALL uart_wr_byte

; r

LOAD uart_data , ASCII_R_LC

CALL uart_wr_byte

; l

LOAD uart_data , ASCII_L_LC

CALL uart_wr_byte

; d

LOAD uart_data , ASCII_D_LC

CALL uart_wr_byte

; !

LOAD uart_data , ASCII_EXCLAMATION_MARK_SIGN

CALL uart_wr_byte

; new line

LOAD uart_data , ASCII_CR_CHAR

CALL uart_wr_byte

LOAD uart_data , ASCII_LF_CHAR

CALL uart_wr_byte

; simple loopback of uart data

mainloop:

  CALL uart_rd_byte

  CALL uart_wr_byte

  JUMP mainloop

; wbs_uart module subroutines and settings

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; usage:

; 1. set baud rate in uart_init subroutine

; 2. call uart_init subroutine to configure wbs_uart module for operation

; 3. use uart_wr_byte and uart_rd_byte subroutines to access uart transceiver,

;    all accesses are blocking, subroutines do not return, if wbs_uart tx buffer

;    is full or rx buffer is empty

;    uart write code =>

;    LOAD uart_data ,  ; setting up data

;    CALL uart_wr_byte ; writing data to uart module

;    

;    uart read code =>

;    CALL uart_rd_byte ; reading data from uart module

;    LOAD  , uart_data ; uart_data is updated now

;    

; 4. uart_clr_buff subroutine can be used to discard wbs_uart rx buffer contents

;    during software runtime

; uart start-up configuration, i. e. baudrate

uart_init:

  ; setting baud rate

  LOAD wb_addr , UART_BAUD_LO_ADDR

  LOAD wb_data , UART_BAUD_LO_115200_VALUE

  CALL wb_wr

  LOAD wb_addr , UART_BAUD_HI_ADDR

  LOAD wb_data , UART_BAUD_HI_115200_VALUE

  CALL wb_wr

  ; clear uart receive buffer, after power up and change of baud rate, there is

  ; maybe invalid data in it

  CALL uart_clr_buff

RETURN

; blocking write byte to uart

uart_wr_byte:

  LOAD wb_addr , UART_RXTX_ADDR

  LOAD wb_data , uart_data

  CALL wb_wr

RETURN

; blocking read byte from uart

uart_rd_byte:

  LOAD wb_addr , UART_RXTX_ADDR

  CALL wb_rd

  LOAD uart_data , wb_data

RETURN

; uart rx buffer clear

uart_clr_buff:

  ; uart receive buffer software reset, checking status register for level and

  ; reading out all available data

  LOAD wb_addr , UART_SR_ADDR ; setting status register address

  CALL wb_rd

  ; checking data present flag

  TEST wb_data , UART_SR_RX_DP_FLAG

  ; if flag is not set, returning immediately

  RETURN Z

  ; else reading out next byte and checking flag again

  CALL uart_rd_byte

  JUMP uart_clr_buff

; register and flag addressing

CONSTANT UART_RXTX_ADDR , 00 ; receive/transmit data pipe

CONSTANT UART_SR_ADDR , 01 ; status register

CONSTANT UART_SR_RX_F_FLAG , 01 ; status rx full

CONSTANT UART_SR_RX_HF_FLAG , 02 ; status rx half full

CONSTANT UART_SR_RX_DP_FLAG , 04 ; status rx data present

CONSTANT UART_SR_TX_F_FLAG , 10 ; status tx full

CONSTANT UART_SR_TX_HF_FLAG , 20 ; status tx half full

CONSTANT UART_BAUD_LO_ADDR , 02 ; baud rate cfg. register / low byte

CONSTANT UART_BAUD_HI_ADDR , 03 ; baud rate cfg. register / high byte

; baud rate configuration:

; baud_limit = round( system clock frequency / (16 * baud rate) ) - 1

; i. e. 9600 baud at 50 MHz system clock =>

; baud_limit = round( 50.0E6 / (16 * 9600) ) - 1 = 325 = 0x0145

; WARNING, baud rate error should not exceed 1.0 % for reliable operation!

; baud rate settings for 50.0E6 Hz system reference clock

; max. 3125000.0 baud

; min. 48.0 baud (16 bit baud timer)

CONSTANT UART_BAUD_LO_300_VALUE , B0 ; actual baud rate 299.99

CONSTANT UART_BAUD_HI_300_VALUE , 28 ; => baud rate error 0.003 %

CONSTANT UART_BAUD_LO_600_VALUE , 57 ; actual baud rate 600.04

CONSTANT UART_BAUD_HI_600_VALUE , 14 ; => baud rate error 0.006 %

CONSTANT UART_BAUD_LO_1200_VALUE , 2B ; actual baud rate 1200.08

CONSTANT UART_BAUD_HI_1200_VALUE , 0A ; => baud rate error 0.006 %

CONSTANT UART_BAUD_LO_2400_VALUE , 15 ; actual baud rate 2400.15

CONSTANT UART_BAUD_HI_2400_VALUE , 05 ; => baud rate error 0.006 %

CONSTANT UART_BAUD_LO_4800_VALUE , 8A ; actual baud rate 4800.31

CONSTANT UART_BAUD_HI_4800_VALUE , 02 ; => baud rate error 0.006 %

CONSTANT UART_BAUD_LO_9600_VALUE , 45 ; actual baud rate 9585.89

CONSTANT UART_BAUD_HI_9600_VALUE , 01 ; => baud rate error 0.147 %

CONSTANT UART_BAUD_LO_19200_VALUE , A2 ; actual baud rate 19171.78

CONSTANT UART_BAUD_HI_19200_VALUE , 00 ; => baud rate error 0.147 %

CONSTANT UART_BAUD_LO_38400_VALUE , 50 ; actual baud rate 38580.25

CONSTANT UART_BAUD_HI_38400_VALUE , 00 ; => baud rate error 0.467 %

CONSTANT UART_BAUD_LO_57600_VALUE , 35 ; actual baud rate 57870.37

CONSTANT UART_BAUD_HI_57600_VALUE , 00 ; => baud rate error 0.467 %

CONSTANT UART_BAUD_LO_115200_VALUE , 1A ; actual baud rate 115740.74

CONSTANT UART_BAUD_HI_115200_VALUE , 00 ; => baud rate error 0.467 %

;CONSTANT UART_BAUD_LO_230400_VALUE , 0D ; actual baud rate 223214.29

;CONSTANT UART_BAUD_HI_230400_VALUE , 00 ; => baud rate error 3.219 %

;CONSTANT UART_BAUD_LO_460800_VALUE , 06 ; actual baud rate 446428.57

;CONSTANT UART_BAUD_HI_460800_VALUE , 00 ; => baud rate error 3.219 %

;CONSTANT UART_BAUD_LO_921600_VALUE , 02 ; actual baud rate 1041666.67

;CONSTANT UART_BAUD_HI_921600_VALUE , 00 ; => baud rate error 11.526 %

; wbm_picoblaze module subroutines and settings

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; subroutines wb_wr and wb_rd are working together with external wbm_picoblaze

; wishbone adapter module and therefore should not be modified. wb_wait_on_ack

; is a supporting subroutine, which should not be called directly

;

; transfer principle wishbone write:

; 1. OUTPUT cycle to set up wishbone address, data and control signals from

;    PORT_ID, OUT_PORT and WRITE_STROBE

; 2. INPUT cycle(s) to poll wishbone peripheral acknowledgement using IN_PORT

; => at least one OUTPUT and one INPUT cycle for a write

;

; transfer principle wishbone read:

; 1. INPUT cycle to set up wishbone address and control signals from PORT_ID

;    and READ_STROBE

; 2. INPUT cycle(s) to poll wishbone peripheral acknowledgement using IN_PORT

; 3. the very next INPUT cycle after acknowledgement contains valid wishbone

;    data from IN_PORT

; => at least three INPUT cycles for a read

;

; calling examples:

;

; wishbone write code =>

;

; LOAD wb_addr ,  ; setting up address

; LOAD wb_data ,  ; setting up data

; CALL wb_wr ; starting wishbone write cycle

;  ; wishbone cycle finished

;

; wishbone read code =>

;

; LOAD wb_addr ,  ; setting up address

; CALL wb_rd ; starting wishbone read cycle

; LOAD  , wb_data ; wb_data is updated now

;  ; wishbone cycle finished

; wishbone write access

wb_wr:

  OUTPUT wb_data , (wb_addr)

  CALL wb_wait_on_ack

RETURN

; wishbone read access

wb_rd:

  CALL wb_wait_on_ack

  INPUT wb_data , (wb_addr)

RETURN

; waiting on wishbone cycle to complete

wb_wait_on_ack:

  INPUT wb_data , (wb_addr)

  TEST wb_data , WB_ACK_FLAG

  JUMP Z , wb_wait_on_ack

RETURN

CONSTANT WB_ACK_FLAG , 01

; interrupt subroutines and settings

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; IMPORTANT NOTICE!

; be carefull, if using interrupts. wishbone cycles must be atomar, as any

; other processor local bus cycles are normally be. interrupting wishbone

; access may cause a crash of external wishbone master fsm, especially, if

; program flow through isr leads to another wishbone cycle!

; interrupt handling template, if needed

isr:

RETURNI DISABLE

ADDRESS 3FF

JUMP isr

; ascii table

;;;;;;;;;;;;;

CONSTANT ASCII_NUL_CHAR , 00 ; NUL

CONSTANT ASCII_SOH_CHAR , 01 ; SOH

CONSTANT ASCII_STX_CHAR , 02 ; STX

CONSTANT ASCII_ETX_CHAR , 03 ; ETX

CONSTANT ASCII_EOT_CHAR , 04 ; EOT

CONSTANT ASCII_ENQ_CHAR , 05 ; ENQ

CONSTANT ASCII_ACK_CHAR , 06 ; ACK

CONSTANT ASCII_BEL_CHAR , 07 ; BEL

CONSTANT ASCII_BS_CHAR , 08 ; BS

CONSTANT ASCII_TAB_CHAR , 09 ; TAB

CONSTANT ASCII_LF_CHAR , 0A ; LF

CONSTANT ASCII_VT_CHAR , 0B ; VT

CONSTANT ASCII_FF_CHAR , 0C ; FF

CONSTANT ASCII_CR_CHAR , 0D ; CR

CONSTANT ASCII_SO_CHAR , 0E ; SO

CONSTANT ASCII_SI_CHAR , 0F ; SI

CONSTANT ASCII_DLE_CHAR , 10 ; DLE

CONSTANT ASCII_DC1_CHAR , 11 ; DC1

CONSTANT ASCII_DC2_CHAR , 12 ; DC2

CONSTANT ASCII_DC3_CHAR , 13 ; DC3

CONSTANT ASCII_DC4_CHAR , 14 ; DC4

CONSTANT ASCII_NAK_CHAR , 15 ; NAK

CONSTANT ASCII_SYN_CHAR , 16 ; SYN

CONSTANT ASCII_ETB_CHAR , 17 ; ETB

CONSTANT ASCII_CAN_CHAR , 18 ; CAN

CONSTANT ASCII_EM_CHAR , 19 ; EM

CONSTANT ASCII_SUB_CHAR , 1A ; SUB

CONSTANT ASCII_ESC_CHAR , 1B ; ESC

CONSTANT ASCII_FS_CHAR , 1C ; FS

CONSTANT ASCII_GS_CHAR , 1D ; GS

CONSTANT ASCII_RS_CHAR , 1E ; RS

CONSTANT ASCII_US_CHAR , 1F ; US

CONSTANT ASCII_SP_CHAR , 20 ; SP

CONSTANT ASCII_EXCLAMATION_MARK_SIGN , 21 ; !

CONSTANT ASCII_DOUBLE_QUOTE_SIGN , 22 ; "

CONSTANT ASCII_NUMBER_SIGN , 23 ; #

CONSTANT ASCII_DOLLAR_SIGN , 24 ; $

CONSTANT ASCII_PERCENT_SIGN , 25 ; %

CONSTANT ASCII_AMPERSAND_SIGN , 26 ; &

CONSTANT ASCII_SINGLE_QUOTE_SIGN , 27 ; '

CONSTANT ASCII_OPN_PARENTHESIS_SIGN , 28 ; (

CONSTANT ASCII_CLS_PARENTHESIS_SIGN , 29 ; )

CONSTANT ASCII_ASTERISK_SIGN , 2A ; *

CONSTANT ASCII_PLUS_SIGN , 2B ; +

CONSTANT ASCII_COMMA_SIGN , 2C ; ,

CONSTANT ASCII_MINUS_SIGN , 2D ; -

CONSTANT ASCII_DOT_SIGN , 2E ; .

CONSTANT ASCII_SLASH_SIGN , 2F ; /

CONSTANT ASCII_0_DIGIT , 30 ; 0

CONSTANT ASCII_1_DIGIT , 31 ; 1

CONSTANT ASCII_2_DIGIT , 32 ; 2

CONSTANT ASCII_3_DIGIT , 33 ; 3

CONSTANT ASCII_4_DIGIT , 34 ; 4

CONSTANT ASCII_5_DIGIT , 35 ; 5

CONSTANT ASCII_6_DIGIT , 36 ; 6

CONSTANT ASCII_7_DIGIT , 37 ; 7

CONSTANT ASCII_8_DIGIT , 38 ; 8

CONSTANT ASCII_9_DIGIT , 39 ; 9

CONSTANT ASCII_COLON_SIGN , 3A ; :

CONSTANT ASCII_SEMICOLON_SIGN , 3B ; ;

CONSTANT ASCII_LESS_THAN_SIGN , 3C ; <

CONSTANT ASCII_EQUAL_SIGN , 3D ; =

CONSTANT ASCII_GREATER_THAN_SIGN , 3E ; >

CONSTANT ASCII_QUESTION_MARK_SIGN , 3F ; ?

CONSTANT ASCII_AT_SIGN , 40 ; @

CONSTANT ASCII_A_UC , 41 ; A

CONSTANT ASCII_B_UC , 42 ; B

CONSTANT ASCII_C_UC , 43 ; C

CONSTANT ASCII_D_UC , 44 ; D

CONSTANT ASCII_E_UC , 45 ; E

CONSTANT ASCII_F_UC , 46 ; F

CONSTANT ASCII_G_UC , 47 ; G

CONSTANT ASCII_H_UC , 48 ; H

CONSTANT ASCII_I_UC , 49 ; I

CONSTANT ASCII_J_UC , 4A ; J

CONSTANT ASCII_K_UC , 4B ; K

CONSTANT ASCII_L_UC , 4C ; L

CONSTANT ASCII_M_UC , 4D ; M

CONSTANT ASCII_N_UC , 4E ; N

CONSTANT ASCII_O_UC , 4F ; O

CONSTANT ASCII_P_UC , 50 ; P

CONSTANT ASCII_Q_UC , 51 ; Q

CONSTANT ASCII_R_UC , 52 ; R

CONSTANT ASCII_S_UC , 53 ; S

CONSTANT ASCII_T_UC , 54 ; T

CONSTANT ASCII_U_UC , 55 ; U

CONSTANT ASCII_V_UC , 56 ; V

CONSTANT ASCII_W_UC , 57 ; W

CONSTANT ASCII_X_UC , 58 ; X

CONSTANT ASCII_Y_UC , 59 ; Y

CONSTANT ASCII_Z_UC , 5A ; Z

CONSTANT ASCII_OPN_BRACKET_SIGN , 5B ; [

CONSTANT ASCII_BACKSLASH_SIGN , 5C ; \

CONSTANT ASCII_CLS_BRACKET_SIGN , 5D ; ]

CONSTANT ASCII_CARET_SIGN , 5E ; ^

CONSTANT ASCII_UNDERSCORE_SIGN , 5F ; _

CONSTANT ASCII_ACCENT_SIGN , 60 ; `

CONSTANT ASCII_A_LC , 61 ; a

CONSTANT ASCII_B_LC , 62 ; b

CONSTANT ASCII_C_LC , 63 ; c

CONSTANT ASCII_D_LC , 64 ; d

CONSTANT ASCII_E_LC , 65 ; e

CONSTANT ASCII_F_LC , 66 ; f

CONSTANT ASCII_G_LC , 67 ; g

CONSTANT ASCII_H_LC , 68 ; h

CONSTANT ASCII_I_LC , 69 ; i

CONSTANT ASCII_J_LC , 6A ; j

CONSTANT ASCII_K_LC , 6B ; k

CONSTANT ASCII_L_LC , 6C ; l

CONSTANT ASCII_M_LC , 6D ; m

CONSTANT ASCII_N_LC , 6E ; n

CONSTANT ASCII_O_LC , 6F ; o

CONSTANT ASCII_P_LC , 70 ; p

CONSTANT ASCII_Q_LC , 71 ; q

CONSTANT ASCII_R_LC , 72 ; r

CONSTANT ASCII_S_LC , 73 ; s

CONSTANT ASCII_T_LC , 74 ; t

CONSTANT ASCII_U_LC , 75 ; u

CONSTANT ASCII_V_LC , 76 ; v

CONSTANT ASCII_W_LC , 77 ; w

CONSTANT ASCII_X_LC , 78 ; x

CONSTANT ASCII_Y_LC , 79 ; y

CONSTANT ASCII_Z_LC , 7A ; z

CONSTANT ASCII_OPN_BRACE_SIGN , 7B ; {

CONSTANT ASCII_VERTICAL_BAR_SIGN , 7C ; |

CONSTANT ASCII_CLS_BRACE_SIGN , 7D ; }

CONSTANT ASCII_TILDE_SIGN , 7E ; ~

CONSTANT ASCII_DEL_CHAR , 7F ; DEL