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T80: tweak NMI trigger.

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This commit is contained in:
sorgelig
2018-08-18 23:28:28 +08:00
parent 89b14cc283
commit 98d825daee
1 changed files with 12 additions and 27 deletions
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39
t80/T80.vhd
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@@ -1034,37 +1034,13 @@ begin
IORQ <= IORQ_i;
Stop <= I_DJNZ;
-------------------------------------------------------------------------
--
-- Syncronise inputs
--
-------------------------------------------------------------------------
process (RESET_n, CLK_n)
variable OldNMI_n : std_logic;
begin
if RESET_n = '0' then
BusReq_s <= '0';
NMI_s <= '0';
OldNMI_n := '0';
elsif rising_edge(CLK_n) then
if CEN = '1' then
BusReq_s <= not BUSRQ_n;
if NMICycle = '1' then
NMI_s <= '0';
elsif NMI_n = '0' and OldNMI_n = '1' then
NMI_s <= '1';
end if;
OldNMI_n := NMI_n;
end if;
end if;
end process;
-------------------------------------------------------------------------
--
-- Main state machine
--
-------------------------------------------------------------------------
process (RESET_n, CLK_n)
variable OldNMI_n : std_logic;
begin
if RESET_n = '0' then
MCycle <= "001";
@@ -1080,9 +1056,17 @@ begin
Auto_Wait_t1 <= '0';
Auto_Wait_t2 <= '0';
M1_n <= '1';
BusReq_s <= '0';
NMI_s <= '0';
elsif rising_edge(CLK_n) then
if CEN = '1' then
if NMI_n = '0' and OldNMI_n = '1' then
NMI_s <= '1';
end if;
OldNMI_n := NMI_n;
if CEN = '1' then
BusReq_s <= not BUSRQ_n;
Auto_Wait_t2 <= Auto_Wait_t1;
if T_Res = '1' then
Auto_Wait_t1 <= '0';
@@ -1139,7 +1123,8 @@ begin
MCycle <= "001";
IntCycle <= '0';
NMICycle <= '0';
if NMI_s = '1' and Prefix = "00" then
if NMI_s = '1' and Prefix = "00" then
NMI_s <= '0';
NMICycle <= '1';
IntE_FF1 <= '0';
elsif IntE_FF1 = '1' and INT_n='0' and Prefix = "00" and SetEI = '0' then