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- redesigned FSM. Zero leadin, zeroleadout and zero release is now possible

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- added assertion check for zero r/w-pulses
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git-svn-id: http://moon:8086/svn/vhdl/trunk@535 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2009-10-27 21:25:36 +00:00
parent c8306cafc4
commit 8b49c6197c
1 changed files with 61 additions and 57 deletions
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lib/misc/async_port_wb.vhd
+61 -57
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@@ -1,5 +1,5 @@
-----------------------------------------------------------------------
-- $Header: /tmp/cvsroot/VHDL/lib/misc/async_port_wb.vhd,v 1.5 2009-02-08 17:34:18 Jens Exp $
-- $Header: /tmp/cvsroot/VHDL/lib/misc/async_port_wb.vhd,v 1.6 2009-10-27 21:25:36 Jens Exp $
-----------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
@@ -49,7 +49,7 @@ architecture Behavioral of async_port_wb is
drive_d : std_logic;
end record;
type async_state_t is (start, reset, idle, leadin_rd, read, leadin_wr, write, leadout_rd, leadout_wr, release);
type async_state_t is (start, reset, idle, leadin, pulse, leadout, release);
signal s, sn : async_state_t;
signal as : async_t;
@@ -62,9 +62,13 @@ architecture Behavioral of async_port_wb is
signal en : std_logic;
signal data_reg : unsigned(data_width-1 downto 0);
signal byte_en : unsigned(byte_sel_width-1 downto 0);
signal write : std_logic;
------------------------------------------------------------------
begin
ASSERT async_timespec.ncyc_pulse_rd > 0 report "Read pulse length must be greater than zero!" severity failure;
ASSERT async_timespec.ncyc_pulse_wr > 0 report "Write pulse length must be greater than zero!" severity failure;
SRDY_O <= CYC_I and rdyo;
en <= CYC_I and STB_I;
@@ -95,7 +99,7 @@ architecture Behavioral of async_port_wb is
end process;
proc_state:
process(s, cycle_cnt, en, WE_I)
process(s, cycle_cnt, en, write, WE_I)
begin
cycle_reload <= async_timespec.ncyc_pulse_rst;
@@ -124,73 +128,72 @@ architecture Behavioral of async_port_wb is
if en = '1' then
as.cs <= '1';
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_access-1;
if WE_I = '0' then
sn <= leadin_rd;
if async_timespec.ncyc_leadin = 0 then
sn <= pulse;
if WE_I = '1' then
cycle_reload <= async_timespec.ncyc_pulse_wr-1;
as.wr <= '1';
as.drive_d <= '1';
else
cycle_reload <= async_timespec.ncyc_pulse_rd-1;
as.rd <= '1';
end if;
else
sn <= leadin_wr;
cycle_reload <= async_timespec.ncyc_leadin-1;
sn <= leadin;
end if;
end if;
when leadin =>
as.cs <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
sn <= pulse;
if write = '1' then
cycle_reload <= async_timespec.ncyc_pulse_wr-1;
as.wr <= '1';
as.drive_d <= '1';
else
cycle_reload <= async_timespec.ncyc_pulse_rd-1;
as.rd <= '1';
end if;
end if;
when leadin_rd =>
when pulse =>
as.cs <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_pulse_rd-1;
as.rd <= '1';
sn <= read;
end if;
when leadin_wr =>
as.cs <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_pulse_wr-1;
as.wr <= '1';
as.drive_d <= '1';
sn <= write;
end if;
when read =>
as.cs <= '1';
as.rd <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_cs_hold-1;
-- as.rd <= '0';
sn <= leadout_rd;
ack <= '1';
end if;
when write =>
as.drive_d <= '1';
as.cs <= '1';
as.wr <= '1';
as.rd <= not write;
as.drive_d <= write;
as.wr <= write;
if cycle_cnt = 0 then
as.wr <= '0';
as.rd <= '0';
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_cs_hold-1;
sn <= leadout_wr;
-- ack <= '1';
ack <= not write;
if async_timespec.ncyc_leadout = 0 then
as.cs <= '0';
if async_timespec.ncyc_release = 0 then
sn <= idle;
else
cycle_reload <= async_timespec.ncyc_release-1;
sn <= release;
end if;
else
cycle_reload <= async_timespec.ncyc_leadout-1;
sn <= leadout;
end if;
end if;
when leadout_rd =>
when leadout =>
as.cs <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_release-1;
sn <= release;
as.cs <= '0';
end if;
when leadout_wr =>
as.cs <= '1';
as.drive_d <= '1';
if cycle_cnt = 0 then
cc_rst <= '1';
cycle_reload <= async_timespec.ncyc_release-1;
sn <= release;
as.cs <= '0';
if async_timespec.ncyc_release = 0 then
sn <= idle;
else
cycle_reload <= async_timespec.ncyc_release-1;
sn <= release;
end if;
end if;
when release =>
@@ -250,6 +253,7 @@ architecture Behavioral of async_port_wb is
if rising_edge(CLK_I) then
if en = '1' and rdy = '1' then
data_reg <= DAT_I(data_width-1 downto 0);
write <= WE_I;
end if;
end if;
end process;