RAM2GS/CPLD/RAM2GS-LCMXO2.v
2024-01-06 21:52:05 -05:00

619 lines
21 KiB
Verilog

module RAM2GS(PHI2, MAin, CROW, Din, Dout,
nCCAS, nCRAS, nFWE, LED,
RBA, RA, RD, nRCS, RCLK, RCLKout, RCKE,
nRWE, nRRAS, nRCAS, RDQMH, RDQML);
/* 65816 Phase 2 Clock */
input PHI2;
/* Async. DRAM Control Inputs */
input nCCAS, nCRAS;
/* Synchronized PHI2 and DRAM signals */
reg PHI2r, PHI2r2, PHI2r3;
reg RASr, RASr2, RASr3;
reg CASr, CASr2, CASr3;
reg FWEr;
reg CBR;
/* Activity LED */
reg LEDEN;
output LED;
assign LED = !(!nCRAS && !CBR && LEDEN && Ready);
/* 65816 Data */
input [7:0] Din;
output [7:0] Dout;
assign Dout[7:0] = RD[7:0];
/* Latched 65816 Bank Address */
reg [7:0] Bank;
/* Async. DRAM Address Bus */
input [1:0] CROW;
input [9:0] MAin;
input nFWE;
reg n8MEGEN = 0;
reg XOR8MEG = 0;
/* SDRAM Clock in/out */
input RCLK;
output RCLKout;
ODDRXE rclk_oddr(.D0(1'b0), .D1(1'b1),
.SCLK(RCLK), .RST(1'b0), .Q(RCLKout));
/* SDRAM */
reg RCKEEN;
output reg RCKE = 0;
output reg nRCS = 1, nRRAS = 1, nRCAS = 1, nRWE = 1;
output reg [1:0] RBA;
reg nRowColSel;
reg RA11;
reg RA10;
reg [9:0] RowA;
output [11:0] RA;
assign RA[11] = RA11;
assign RA[10] = RA10;
assign RA[9:0] = !nRowColSel ? RowA[9:0] : MAin[9:0];
output RDQML, RDQMH;
assign RDQML = !nRowColSel ? 1'b1 : !MAin[9];
assign RDQMH = !nRowColSel ? 1'b1 : MAin[9];
reg [7:0] WRD;
inout [7:0] RD;
assign RD[7:0] = (!nCCAS && !nFWE) ? WRD[7:0] : 8'bZ;
/* UFM Interface */
reg wb_rst;
reg wb_cyc_stb;
reg wb_req;
reg wb_we;
reg [7:0] wb_adr;
reg [7:0] wb_dati;
wire wb_ack;
wire [7:0] wb_dato;
wire ufm_irq;
REFB ufmefb (
.wb_clk_i(RCLK),
.wb_rst_i(wb_rst),
.wb_cyc_i(wb_cyc_stb),
.wb_stb_i(wb_cyc_stb),
.wb_we_i(wb_we),
.wb_adr_i(wb_adr),
.wb_dat_i(wb_dati),
.wb_dat_o(wb_dato),
.wb_ack_o(wb_ack),
.wbc_ufm_irq(ufm_irq));
/* UFM Command Interface */
reg C1Submitted = 0;
reg ADSubmitted = 0;
reg CmdEnable = 0;
reg CmdValid = 0;
reg Cmdn8MEGEN = 0;
reg CmdLEDEN = 0;
reg CmdUFMWrite = 0;
reg CmdUFMShift = 0;
reg CmdUFMData = 0;
wire ADWR = Bank[7:0]==8'hFB && MAin[7:0]==8'hFF && !nFWE;
wire C1WR = Bank[7:0]==8'hFB && MAin[7:0]==8'hFE && !nFWE;
wire CMDWR = Bank[7:0]==8'hFB && MAin[7:0]==8'hFD && !nFWE;
/* State Counters */
reg InitReady = 0; // 1 if ready for init sequence
reg Ready = 0; // 1 if done with init sequence
reg [1:0] S = 0; // post-RAS State counter
reg [17:0] FS = 0; // Fast init state counter
reg [3:0] IS = 0; // Init state counter
/* Synchronize PHI2, RAS, CAS */
always @(posedge RCLK) begin
PHI2r <= PHI2; PHI2r2 <= PHI2r; PHI2r3 <= PHI2r2;
RASr <= !nCRAS; RASr2 <= RASr; RASr3 <= RASr2;
CASr <= !nCCAS; CASr2 <= CASr; CASr3 <= CASr2;
end
/* Latch 65816 bank when PHI2 rises */
always @(posedge PHI2) begin
if (Ready) RA11 <= (Din[6] && !n8MEGEN) ^ XOR8MEG; // Set RA11
else RA11 <= 1'b0; // Reserved in mode register
Bank[7:0] <= Din[7:0]; // Latch bank
end
/* Latch bank address, row address, WE, and CAS when RAS falls */
always @(negedge nCRAS) begin
if (Ready) begin
RBA[1:0] <= CROW[1:0];
RowA[9:0] <= MAin[9:0];
end else begin
RBA[1:0] <= 2'b00; // Reserved in mode register
RowA[9] <= 1'b1; // "1" for single write mode
RowA[8] <= 1'b0; // Reserved
RowA[7] <= 1'b0; // "0" for not test mode
RowA[6:4] <= 3'b010; // "2" for CAS latency 2
RowA[3] <= 1'b0; // "0" for sequential burst (not used)
RowA[2:0] <= 3'b000; // "0" for burst length 1 (no burst)
end
FWEr <= !nFWE;
CBR <= !nCCAS;
end
/* Latch write data when CAS falls */
always @(negedge nCCAS) begin
WRD[7:0] <= Din[7:0];
end
/* State counter from RAS */
always @(posedge RCLK) begin
if (!RASr2) S <= 0;
else if (S==2'h3) S <= 2'h3;
else S <= S+2'h1;
end
/* Init state counter */
always @(posedge RCLK) begin
// Wait ~4.178ms (at 62.5 MHz) before starting init sequence
FS <= FS+18'h1;
if (FS[17:10]==8'hFF) InitReady <= 1'b1;
end
/* SDRAM CKE */
always @(posedge RCLK) begin
// Only 1 LUT4 allowed for this function!
RCKE <= ((RASr || RASr2) && RCKEEN) || (!RASr2 && RASr3);
end
/* SDRAM command */
always @(posedge RCLK) begin
if (Ready) begin
if (S==0) begin
if (RASr2) begin
if (CBR) begin
// AREF
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b0;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end else begin
// ACT
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // Bank RA10 consistently "1"
end
// Enable clock only for reads
RCKEEN <= !CBR && !FWEr;
end else if (RCKE) begin
// PCall
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b1;
nRWE <= 1'b0;
RA10 <= 1'b1; // "all"
RCKEEN <= 1'b1;
end else begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
RCKEEN <= 1'b1;
end
nRowColSel <= 1'b0; // Select registered row addres
end else if (S==1) begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
nRowColSel <= 1'b1; // Select asynchronous column address
RCKEEN <= !CBR; // Disable clock if refresh cycle
end else if (S==2) begin
if (!FWEr && !CBR) begin
// RD
nRCS <= 1'b0;
nRRAS <= 1'b1;
nRCAS <= 1'b0;
nRWE <= 1'b1;
RA10 <= 1'b1; // Auto-precharge
end else begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end
nRowColSel <= 1'b1; // Select asynchronous column address
RCKEEN <= !CBR && FWEr; // Enable clock only for writes
end else if (S==3) begin
if (CASr2 && !CASr3 && !CBR && FWEr) begin
// WR
nRCS <= 1'b0;
nRRAS <= 1'b1;
nRCAS <= 1'b0;
nRWE <= 1'b0;
RA10 <= 1'b1; // Auto-precharge
end else begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end
nRowColSel <= !(!FWEr || CASr3 || CBR);
RCKEEN <= !(!FWEr || CASr2 || CBR);
end
end else if (InitReady) begin
if (S==0 && RASr2) begin
if (IS==0) begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end else if (IS==1) begin
// PC all
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b1;
nRWE <= 1'b0;
RA10 <= 1'b1; // "all"
end else if (IS==9) begin
// Load mode register
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b0;
nRWE <= 1'b0;
RA10 <= 1'b0; // Reserved in mode register
end else begin
// AREF
nRCS <= 1'b0;
nRRAS <= 1'b0;
nRCAS <= 1'b0;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end
IS <= IS+4'h1;
end else begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
end
if (S==3 && !RASr2 && IS==15) Ready <= 1'b1;
nRowColSel <= 1'b0; // Select registered row address
RCKEEN <= 1'b1;
end else begin
// NOP
nRCS <= 1'b1;
nRRAS <= 1'b1;
nRCAS <= 1'b1;
nRWE <= 1'b1;
RA10 <= 1'b1; // RA10 is don't care
nRowColSel <= 1'b0; // Select registered row address
RCKEEN <= 1'b0;
end
end
/* Submit command when PHI2 falls */
always @(negedge PHI2) begin
// Magic number check
if (C1WR && Din[7:0]==8'hC1) begin // "C1" magic number
if (ADSubmitted) begin
CmdEnable <= 1'b1;
end
C1Submitted <= 1'b1;
ADSubmitted <= 1'b0;
end else if (ADWR && Din[7:0]==8'hAD) begin // "AD" magic number
if (C1Submitted) begin
CmdEnable <= 1'b1;
end
ADSubmitted <= 1'b1;
C1Submitted <= 1'b0;
end else if (C1WR || ADWR) begin // wrong magic number submitted
CmdEnable <= 1'b0;
C1Submitted <= 1'b0;
ADSubmitted <= 1'b0;
end else if (CMDWR) CmdEnable <= 1'b0;
// Submit command
if (CMDWR && CmdEnable) begin
// if (Din[7:4]==4'h0 && Din[3:2]==2'b00) begin // MAX w/LED
// if (Din[7:4]==4'h0) begin // MAX w/o LED
// if (Din[7:4]==4'h0 && Din[3:2]==2'b01) begin // LCMXO / iCE40 / AGM
if (Din[7:4]==4'h0 && Din[3:2]==2'b10) begin // LCMXO2
XOR8MEG <= Din[0] && !(LEDEN && Din[1]);
CmdValid <= 1'b0;
end else if (Din[7:4]==4'h0) begin // Unsupported type
XOR8MEG <= 0;
CmdValid <= 1'b0;
end else if (Din[7:4]==4'h1) begin
CmdLEDEN <= Din[1];
Cmdn8MEGEN <= !Din[0];
CmdUFMShift <= 1'b0;
CmdUFMWrite <= 1'b0;
CmdValid <= 1'b1;
end else if (Din[7:4]==4'h2) begin
// Reserved for MAX commands
CmdValid <= 1'b0;
end else if (Din[7:4]==4'h3 && !Din[3]) begin
// Reserved for SPI (LCMXO, iCE40) commands
// Din[2] - CS
// Din[1] - SCK
// Din[0] - SDI
CmdValid <= 1'b0;
end else if (Din[7:4]==4'h3 && Din[3]) begin
// LCMXO2 commands
// Din[1] - Shift when low, execute when high
// Din[0] - Shift data
CmdUFMShift <= !Din[1];
CmdUFMWrite <= Din[1:0] == 2'b10;
CmdUFMData <= Din[0];
CmdLEDEN <= LEDEN;
Cmdn8MEGEN <= n8MEGEN;
CmdValid <= 1'b1;
end else CmdValid <= 1'b0;
end else CmdValid <= 1'b0;
end
/* UFM Control */
always @(posedge RCLK) begin
if (!InitReady && FS[17:15]==3'h0) begin
wb_rst <= !FS[14];
wb_we <= 1'b0;
wb_cyc_stb <= 1'b0;
wb_req <= 1'b0;
wb_adr[7:0] <= 8'h00;
wb_dati[7:0] <= 8'h00;
end else if (!InitReady && FS[17:15]==3'h1) begin
wb_rst <= 1'b0;
if (FS[8:0]==0) wb_cyc_stb <= 0;
else if (FS[8:0]==1 && wb_req) wb_cyc_stb <= 1;
else if (wb_ack) wb_cyc_stb <= 0;
case (FS[14:9])
0: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 1: begin // Enable configuration interface - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h74;
wb_req <= 1;
end 2: begin // Enable configuration interface - operand 1/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h08;
wb_req <= 1;
end 3: begin // Enable configuration interface - operand 2/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 4: begin // Enable configuration interface - operand 3/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 5: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 6: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 7: begin // Poll status register - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h3C;
wb_req <= 1;
end 8: begin // Poll status register - operand 1/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 9: begin // Poll status register - operand 2/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 10: begin // Poll status register - operand 3/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 11, 12, 13, 14: begin // Read status register 1-4
wb_we <= 1'b0;
wb_adr[7:0] <= 8'h73;
wb_dati[7:0] <= 8'h3C;
wb_req <= 1;
end 15: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 16: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 17: begin // Set UFM address - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'hB4;
wb_req <= 1;
end 18: begin // Set UFM address - operand 1/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 19: begin // Set UFM address - operand 2/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 20: begin // Set UFM address - operand 3/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 21: begin // Set UFM address - data 1/4
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h40;
wb_req <= 1;
end 22: begin // Set UFM address - data 2/4
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 23: begin // Set UFM address - data 3/4
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 24: begin // Set UFM address - data 4/4
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 190;
wb_req <= 1;
end 25: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 26: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 27: begin // Read UFM page - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'hCA;
wb_req <= 1;
end 28: begin // Read UFM page - operand 1/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h10;
wb_req <= 1;
end 29: begin // Read UFM page - operand 2/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 30: begin // Read UFM page - operand 3/3
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h01;
wb_req <= 1;
end 31: begin // Read UFM page - data 0
wb_we <= 1'b0;
wb_adr[7:0] <= 8'h73;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
if (wb_ack) begin
LEDEN <= wb_dato[1];
n8MEGEN <= wb_dato[0];
end
end 32, 33, 34,
35, 36, 37, 38,
39, 40, 41, 42,
43, 44, 45, 46: begin // Read UFM page - data 1-15
wb_we <= 1'b0;
wb_adr[7:0] <= 8'h73;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 47: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 48: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 49: begin // Disable configuration interface - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h26;
wb_req <= 1;
end 50: begin // Disable configuration interface - operand 1/2
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 51: begin // Disable configuration interface - operand 2/2
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 52: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end 53: begin // Open frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h80;
wb_req <= 1;
end 54: begin // Bypass - command
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h71;
wb_dati[7:0] <= 8'hFF;
wb_req <= 1;
end 55: begin // Close frame
wb_we <= 1'b1;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 1;
end default: begin
wb_we <= 1'b0;
wb_adr[7:0] <= 8'h70;
wb_dati[7:0] <= 8'h00;
wb_req <= 0;
end
endcase
end else if (!InitReady) begin
wb_rst <= 1'b0;
wb_cyc_stb <= 1'b0;
wb_req <= 1'b0;
wb_we <= 1'b0;
wb_adr[7:0] <= 8'h00;
wb_dati[7:0] <= 8'h00;
end else if (!PHI2r2 && PHI2r3 && CmdValid) begin
wb_rst <= 1'b0;
wb_req <= 1'b0;
// Set user command signals after PHI2 falls
LEDEN <= CmdLEDEN;
n8MEGEN <= Cmdn8MEGEN;
if (CmdUFMShift) begin
wb_adr[7:0] <= { wb_adr[6:0], wb_dati[7] };
wb_dati[7:0] <= { wb_dati[6:0], wb_we };
wb_we <= CmdUFMData;
end
wb_cyc_stb <= CmdUFMWrite;
end else wb_cyc_stb <= 0;
end
endmodule