URL
https://opencores.org/ocsvn/w11/w11/trunk
Subversion Repositories w11
[/] [w11/] [tags/] [w11a_V0.5/] [rtl/] [bplib/] [s3board/] [s3_sram_memctl.vhd] - Rev 37
Go to most recent revision | Compare with Previous | Blame | View Log
-- $Id: s3_sram_memctl.vhd 314 2010-07-09 17:38:41Z mueller $ -- -- Copyright 2007-2010 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de> -- -- This program is free software; you may redistribute and/or modify it under -- the terms of the GNU General Public License as published by the Free -- Software Foundation, either version 2, or at your option any later version. -- -- This program is distributed in the hope that it will be useful, but -- WITHOUT ANY WARRANTY, without even the implied warranty of MERCHANTABILITY -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- for complete details. -- ------------------------------------------------------------------------------ -- Module Name: s3_sram_memctl - syn -- Description: s3board: SRAM driver -- -- Dependencies: vlib/xlib/iob_reg_o -- vlib/xlib/iob_reg_o_gen -- vlib/xlib/iob_reg_io_gen -- Test bench: tb/tb_s3_sram_memctl -- fw_gen/tst_sram/s3board/tb/tb_tst_sram_s3 -- Target Devices: generic -- Tool versions: xst 8.1, 8.2, 9.1, 9.2; ghdl 0.18-0.25 -- -- Synthesized (xst): -- Date Rev ise Target flop lutl lutm slic t peri -- 2010-05-23 293 11.4 L68 xc3s1000-4 7 22 0 14 s 8.5 -- 2008-02-16 116 8.2.03 I34 xc3s1000-4 5 30 0 17 s 7.0 -- -- Revision History: -- Date Rev Version Comment -- 2010-06-03 299 1.0.5 add "KEEP" for data iob; -- 2010-05-16 291 1.0.4 rename memctl_s3sram -> s3_sram_memctl -- 2008-02-17 117 1.0.3 use req,we rather req_r,req_w interface -- 2008-01-20 113 1.0.2 rename memdrv -> memctl_s3sram -- 2007-12-15 101 1.0.1 use _N for active low; get ce/we clocking right -- 2007-12-08 100 1.0 Initial version -- -- Timing of some signals: -- -- single read request: -- -- state |_idle |_read |_idle | -- -- CLK __|^^^|___|^^^|___|^^^|___|^ -- -- REQ _______|^^^^^|______________ -- WE ____________________________ -- -- IOB_CE __________|^^^^^^^|_________ -- IOB_OE __________|^^^^^^^|_________ -- -- DO oooooooooooooooooo|ddddddd|d -- BUSY ____________________________ -- ACK_R __________________|^^^^^^^|_ -- -- single write request: -- -- state |_idle |_write1|_write2|_idle | -- -- CLK __|^^^|___|^^^|___|^^^|___|^^^|___|^ -- -- REQ _______|^^^^^|______________ -- WE _______|^^^^^|______________ -- -- IOB_CE __________|^^^^^^^^^^^^^^^|_________ -- IOB_BE __________|^^^^^^^^^^^^^^^|_________ -- IOB_OE ____________________________________ -- IOB_WE ______________|^^^^^^^|_____________ -- -- BUSY __________|^^^^^^^|_________________ -- ACK_W __________________|^^^^^^^|_________ -- ------------------------------------------------------------------------------ library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use work.slvtypes.all; use work.xlib.all; entity s3_sram_memctl is -- SRAM driver for S3BOARD port ( CLK : in slbit; -- clock RESET : in slbit; -- reset REQ : in slbit; -- request WE : in slbit; -- write enable BUSY : out slbit; -- controller busy ACK_R : out slbit; -- acknowledge read ACK_W : out slbit; -- acknowledge write ACT_R : out slbit; -- signal active read ACT_W : out slbit; -- signal active write ADDR : in slv18; -- address BE : in slv4; -- byte enable DI : in slv32; -- data in (memory view) DO : out slv32; -- data out (memory view) O_MEM_CE_N : out slv2; -- sram: chip enables (act.low) O_MEM_BE_N : out slv4; -- sram: byte enables (act.low) O_MEM_WE_N : out slbit; -- sram: write enable (act.low) O_MEM_OE_N : out slbit; -- sram: output enable (act.low) O_MEM_ADDR : out slv18; -- sram: address lines IO_MEM_DATA : inout slv32 -- sram: data lines ); end s3_sram_memctl; architecture syn of s3_sram_memctl is type state_type is ( s_idle, -- s_idle: wait for req s_read, -- s_read: read cycle s_write1, -- s_write1: write cycle, 1st half s_write2, -- s_write2: write cycle, 2nd half s_bta_r2w, -- s_bta_r2w: bus turn around: r->w s_bta_w2r -- s_bta_w2r: bus turn around: w->r ); type regs_type is record state : state_type; -- state ackr : slbit; -- signal ack_r end record regs_type; constant regs_init : regs_type := ( s_idle, '0' -- ackr ); signal R_REGS : regs_type := regs_init; -- state registers signal N_REGS : regs_type := regs_init; -- next value state regs signal CLK_180 : slbit := '0'; signal MEM_CE_N : slv2 := "00"; signal MEM_BE_N : slv4 := "0000"; signal MEM_WE_N : slbit := '0'; signal MEM_OE_N : slbit := '0'; signal ADDR_CE : slbit := '0'; signal DATA_CEI : slbit := '0'; signal DATA_CEO : slbit := '0'; signal DATA_OE : slbit := '0'; begin CLK_180 <= not CLK; IOB_MEM_CE : iob_reg_o_gen generic map ( DWIDTH => 2, INIT => '1') port map ( CLK => CLK, CE => '1', DO => MEM_CE_N, PAD => O_MEM_CE_N ); IOB_MEM_BE : iob_reg_o_gen generic map ( DWIDTH => 4, INIT => '1') port map ( CLK => CLK, CE => ADDR_CE, DO => MEM_BE_N, PAD => O_MEM_BE_N ); IOB_MEM_WE : iob_reg_o generic map ( INIT => '1') port map ( CLK => CLK_180, CE => '1', DO => MEM_WE_N, PAD => O_MEM_WE_N ); IOB_MEM_OE : iob_reg_o generic map ( INIT => '1') port map ( CLK => CLK, CE => '1', DO => MEM_OE_N, PAD => O_MEM_OE_N ); IOB_MEM_ADDR : iob_reg_o_gen generic map ( DWIDTH => 18) port map ( CLK => CLK, CE => ADDR_CE, DO => ADDR, PAD => O_MEM_ADDR ); IOB_MEM_DATA : iob_reg_io_gen generic map ( DWIDTH => 32, PULL => "KEEP") port map ( CLK => CLK, CEI => DATA_CEI, CEO => DATA_CEO, OE => DATA_OE, DI => DO, DO => DI, PAD => IO_MEM_DATA ); proc_regs: process (CLK) begin if CLK'event and CLK='1' then if RESET = '1' then R_REGS <= regs_init; else R_REGS <= N_REGS; end if; end if; end process proc_regs; proc_next: process (R_REGS, REQ, WE, BE) variable r : regs_type := regs_init; variable n : regs_type := regs_init; variable ibusy : slbit := '0'; variable iackw : slbit := '0'; variable iactr : slbit := '0'; variable iactw : slbit := '0'; variable imem_ce : slv2 := "00"; variable imem_be : slv4 := "0000"; variable imem_we : slbit := '0'; variable imem_oe : slbit := '0'; variable iaddr_ce : slbit := '0'; variable idata_cei : slbit := '0'; variable idata_ceo : slbit := '0'; variable idata_oe : slbit := '0'; begin r := R_REGS; n := R_REGS; n.ackr := '0'; ibusy := '0'; iackw := '0'; iactr := '0'; iactw := '0'; imem_ce := "00"; imem_be := "1111"; imem_we := '0'; imem_oe := '0'; iaddr_ce := '0'; idata_cei := '0'; idata_ceo := '0'; idata_oe := '0'; case r.state is when s_idle => -- s_idle: wait for req if REQ = '1' then -- if IO requested if WE = '0' then -- if READ requested iaddr_ce := '1'; -- latch address and be's imem_ce := "11"; -- ce SRAM next cycle imem_oe := '1'; -- oe SRAM next cycle n.state := s_read; -- next: read else -- if WRITE requested iaddr_ce := '1'; -- latch address and be's idata_ceo := '1'; -- latch output data idata_oe := '1'; -- oe FPGA next cycle imem_ce := "11"; -- ce SRAM next cycle imem_be := BE; -- use request BE's n.state := s_write1; -- next: write 1st part end if; end if; when s_read => -- s_read: read cycle idata_cei := '1'; -- latch input data iactr := '1'; -- signal mem read n.ackr := '1'; -- ACK_R next cycle if REQ = '1' then -- if IO requested if WE = '0' then -- if READ requested iaddr_ce := '1'; -- latch address and be's imem_ce := "11"; -- ce SRAM next cycle imem_oe := '1'; -- oe SRAM next cycle n.state := s_read; -- next: continue read else -- if WRITE requested iaddr_ce := '1'; -- latch address and be's idata_ceo := '1'; -- latch output data imem_be := BE; -- use request BE's n.state := s_bta_r2w; -- next: bus turn around cycle end if; else n.state := s_idle; -- next: idle if nothing to do end if; when s_write1 => -- s_write1: write cycle, 1st half ibusy := '1'; -- signal busy, unable to handle req iactw := '1'; -- signal mem write idata_oe := '1'; -- oe FPGA next cycle imem_ce := "11"; -- ce SRAM next cycle imem_we := '1'; -- we SRAM next shifted cycle n.state := s_write2; -- next: write cycle, 2nd half when s_write2 => -- s_write2: write cycle, 2nd half iactw := '1'; -- signal mem write iackw := '1'; -- signal write acknowledge idata_cei := '1'; -- latch input data (from SRAM) if REQ = '1' then -- if IO requested if WE = '1' then -- if WRITE requested iaddr_ce := '1'; -- latch address and be's idata_ceo := '1'; -- latch output data idata_oe := '1'; -- oe FPGA next cycle imem_ce := "11"; -- ce SRAM next cycle imem_be := BE; -- use request BE's n.state := s_write1; -- next: continue read else -- if READ requested iaddr_ce := '1'; -- latch address and be's n.state := s_bta_w2r; -- next: bus turn around cycle end if; else n.state := s_idle; -- next: idle if nothing to do end if; when s_bta_r2w => -- s_bta_r2w: bus turn around: r->w ibusy := '1'; -- signal busy, unable to handle req iactw := '1'; -- signal mem write imem_ce := "11"; -- ce SRAM next cycle idata_oe := '1'; -- oe FPGA next cycle n.state := s_write1; -- next: start write when s_bta_w2r => -- s_bta_w2r: bus turn around: w->r ibusy := '1'; -- signal busy, unable to handle req iactr := '1'; -- signal mem read imem_ce := "11"; -- ce SRAM next cycle imem_oe := '1'; -- oe SRAM next cycle n.state := s_read; -- next: start read when others => null; end case; N_REGS <= n; MEM_CE_N <= not imem_ce; MEM_WE_N <= not imem_we; MEM_BE_N <= not imem_be; MEM_OE_N <= not imem_oe; ADDR_CE <= iaddr_ce; DATA_CEI <= idata_cei; DATA_CEO <= idata_ceo; DATA_OE <= idata_oe; BUSY <= ibusy; ACK_R <= r.ackr; ACK_W <= iackw; ACT_R <= iactr; ACT_W <= iactw; end process proc_next; end syn;
Go to most recent revision | Compare with Previous | Blame | View Log