Apple-2-HW/GR8RAM
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Register reset/initial values set syntax changed

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Zane Kaminski 2019-10-13 01:40:25 -04:00
parent a45778b440
commit 67399312b6
1 changed files with 23 additions and 23 deletions
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46
cpld/GR8RAM.v
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@ -73,24 +73,24 @@ module GR8RAM(C7M, C7M_2, Q3, PHI0in, PHI1in, nRES, nMode,
output nCAS1 = ~(CASr | (CASf & RAMSEL & Addr[22])); // DRAM CAS bank 1
/* 6502-accessible Registers */
reg [7:0] Bank = 8'h00; // Bank register for ROM access
reg [22:0] Addr = 23'h00000; // RAM address register
reg [7:0] Bank = 0; // Bank register for ROM access
reg [22:0] Addr = 0; // RAM address register
/* Increment Control */
reg IncAddrL = 0, IncAddrM = 0, IncAddrH = 0;
/* CAS rising/falling edge components */
// These are combined to create the CAS outputs.
reg CASr = 1'b0;
reg CASf = 1'b0;
reg RASr = 1'b0;
reg RASf = 1'b0;
reg CASr = 0;
reg CASf = 0;
reg RASr = 0;
reg RASf = 0;
/* State Counters */
reg PHI1reg = 1'b0; // Saved PHI1 at last rising clock edge
reg PHI0seen = 1'b0; // Have we seen PHI0 since reset?
reg [2:0] S = 3'h0; // State counter
reg [3:0] Ref = 4'h0; // Refresh skip counter
reg PHI1reg = 0; // Saved PHI1 at last rising clock edge
reg PHI0seen = 0; // Have we seen PHI0 since reset?
reg [2:0] S = 0; // State counter
reg [3:0] Ref = 0; // Refresh skip counter
/* Misc. */
reg REGEN = 0; // Register enable
@ -112,13 +112,13 @@ module GR8RAM(C7M, C7M_2, Q3, PHI0in, PHI1in, nRES, nMode,
always @(posedge C7M, negedge nRES) begin
if (~nRES) begin // Reset
PHI1reg <= 1'b0;
PHI0seen <= 1'b0;
S <= 3'h0;
Ref <= 3'b000;
REGEN <= 1'b0;
IOROMEN <= 1'b0;
CSDBEN <= 1'b0;
PHI1reg <= 0;
PHI0seen <= 0;
S <= 0;
Ref <= 0;
REGEN <= 0;
IOROMEN <= 0;
CSDBEN <= 0;
end else begin
// Synchronize state counter to S1 when just entering PHI1
PHI1reg <= PHI1; // Save old PHI1
@ -151,12 +151,12 @@ module GR8RAM(C7M, C7M_2, Q3, PHI0in, PHI1in, nRES, nMode,
always @(negedge C7M, negedge nRES) begin
if (~nRES) begin
Addr <= 23'h000000;
Bank <= 8'h00;
FullIOEN <= 1'b0;
IncAddrL <= 1'b0;
IncAddrM <= 1'b0;
IncAddrH <= 1'b0;
Addr <= 0;
Bank <= 0;
FullIOEN <= 0;
IncAddrL <= 0;
IncAddrM <= 0;
IncAddrH <= 0;
end else begin
// Increment address register
if (S==1 & IncAddrL) begin