forked from Apple-2-HW/GR8RAM
Sketch of verilog
This commit is contained in:
Zane Kaminski
parent
4beed0e635
commit
3091ea4d32
830
cpld/GR8RAM.v
830
cpld/GR8RAM.v
@ -1,275 +1,599 @@
|
||||
module GR8RAM(C7M, C7M_2, Q3, PHI0in, PHI1in, nRES, nMode,
|
||||
A, RA, nWE, D, RD,
|
||||
nDEVSEL, nIOSEL, nIOSTRB,
|
||||
nRAS, nCAS0, nCAS1, nRCS, nROE, nRWE);
|
||||
module GR8RAM(C25M, PHI1, nIOSEL, nDEVSEL, nIOSTRB,
|
||||
RA, RB6, nRWE, nROE, nAOE, Adir, nRCS,
|
||||
RD, nDOE, Ddir,
|
||||
SBA, SA, nSCS, nRAS, nCAS, nSWE, DQML, DQMH, SCKE, SD,
|
||||
nRST, nPreBOD,
|
||||
DMAin, DMAout, INTin, INTout,
|
||||
nIRQout, nINHout, nDMAout, nNMIout);
|
||||
|
||||
/* Clock, Reset, Mode */
|
||||
input C7M, C7M_2, Q3, PHI0in, PHI1in; // Clock inputs
|
||||
input nRES;
|
||||
/* Clock inputs */
|
||||
input C25M, PHI1;
|
||||
wire PHI0 = ~PHI1;
|
||||
|
||||
/* PHI1 Delay */
|
||||
wire [8:0] PHI1b;
|
||||
wire PHI1;
|
||||
LCELL PHI1b0_MC (.in(PHI1in), .out(PHI1b[0]));
|
||||
LCELL PHI1b1_MC (.in(PHI1b[0]), .out(PHI1b[1]));
|
||||
LCELL PHI1b2_MC (.in(PHI1b[1]), .out(PHI1b[2]));
|
||||
LCELL PHI1b3_MC (.in(PHI1b[2]), .out(PHI1b[3]));
|
||||
LCELL PHI1b4_MC (.in(PHI1b[3]), .out(PHI1b[4]));
|
||||
LCELL PHI1b5_MC (.in(PHI1b[4]), .out(PHI1b[5]));
|
||||
LCELL PHI1b6_MC (.in(PHI1b[5]), .out(PHI1b[6]));
|
||||
LCELL PHI1b7_MC (.in(PHI1b[6]), .out(PHI1b[7]));
|
||||
LCELL PHI1b8_MC (.in(PHI1b[7]), .out(PHI1b[8]));
|
||||
LCELL PHI1b9_MC (.in(PHI1b[8] & PHI1in), .out(PHI1));
|
||||
|
||||
/* Address Bus, etc. */
|
||||
input nDEVSEL, nIOSEL, nIOSTRB; // Card select signals
|
||||
input [15:0] A; // 6502 address bus
|
||||
input nWE; // 6502 R/W
|
||||
output [10:0] RA; // DRAM/ROM address
|
||||
assign RA[10:8] = CASel ? Addr[21:19] : Addr[10:8];
|
||||
assign RA[7:0] =
|
||||
(~nIOSTRB & ~FullIOEN) ? {7'b0000001, Bank[0]} :
|
||||
(~nIOSTRB & FullIOEN) ? Bank+1 :
|
||||
( nIOSTRB & ~CASel & nIOSEL) ? Addr[18:11] :
|
||||
( nIOSTRB & CASel & nIOSEL) ? Addr[7:0] : 8'h00;
|
||||
|
||||
/* Select Signals */
|
||||
wire BankSELA = A[3:0]==4'hF;
|
||||
wire MagicSELA = A[3:0]==4'hE;
|
||||
wire TCntHSELA = A[3:0]==4'hB;
|
||||
wire TCntLSELA = A[3:0]==4'hA;
|
||||
wire DestHSELA = A[3:0]==4'h9;
|
||||
wire DestLSELA = A[3:0]==4'h8;
|
||||
wire RAMSELA = A[3:0]==4'h3;
|
||||
wire AddrHSELA = A[3:0]==4'h2;
|
||||
wire AddrMSELA = A[3:0]==4'h1;
|
||||
wire AddrLSELA = A[3:0]==4'h0;
|
||||
LCELL BankWR_MC (.in(BankSELA & ~nWE & ~nDEVSEL & REGEN), .out(BankWR)); wire BankWR;
|
||||
LCELL MagicWR_MC (.in(MagicSELA & ~nWE & ~nDEVSEL & REGEN), .out(MagicWR)); wire MagicWR;
|
||||
LCELL TCntHWR_MC (.in(TCntHSELA & ~nWE & ~nDEVSEL & REGEN), .out(TCntHWR)); wire TCntHWR;
|
||||
LCELL TCntLWR_MC (.in(TCntLSELA & ~nWE & ~nDEVSEL & REGEN), .out(TCntLWR)); wire TCntLWR;
|
||||
LCELL DestHWR_MC (.in(DestHSELA & ~nWE & ~nDEVSEL & REGEN), .out(DestHWR)); wire DestHWR;
|
||||
LCELL DestLWR_MC (.in(DestLSELA & ~nWE & ~nDEVSEL & REGEN), .out(DestLWR)); wire DestLWR;
|
||||
LCELL RAMSEL_MC (.in(RAMSELA & ~nDEVSEL & REGEN), .out(RAMSEL)); wire RAMSEL;
|
||||
LCELL AddrHWR_MC (.in(AddrHSELA & ~nWE & ~nDEVSEL & REGEN), .out(AddrHWR)); wire AddrHWR;
|
||||
LCELL AddrMWR_MC (.in(AddrMSELA & ~nWE & ~nDEVSEL & REGEN), .out(AddrMWR)); wire AddrMWR;
|
||||
LCELL AddrLWR_MC (.in(AddrLSELA & ~nWE & ~nDEVSEL & REGEN), .out(AddrLWR)); wire AddrLWR;
|
||||
|
||||
/* Data Bus Routing */
|
||||
// DRAM/ROM data bus
|
||||
wire RDOE = DBEN & ~nWE;
|
||||
inout [7:0] RD = RDOE ? D[7:0] : 8'bZ;
|
||||
// Apple II data bus
|
||||
wire DOE = DBEN & nWE &
|
||||
((~nDEVSEL & REGEN) | ~nIOSEL | (~nIOSTRB & IOROMEN));
|
||||
wire [7:0] Dout = (nDEVSEL | RAMSELA) ? RD[7:0] :
|
||||
AddrHSELA ? Addr[23:16] :
|
||||
AddrMSELA ? Addr[15:8] :
|
||||
AddrLSELA ? Addr[7:0] : 8'h00;
|
||||
inout [7:0] D = DOE ? Dout : 8'bZ;
|
||||
|
||||
/* DRAM and ROM Control Signals */
|
||||
output nRCS = ~((~nIOSEL | (~nIOSTRB & IOROMEN)) & CSEN); // ROM chip select
|
||||
output nROE = ~nWE; // need this for flash ROM
|
||||
output nRWE = CASel ? nWE : 1'b1; // for ROM & DRAM
|
||||
output nRAS = ~(RASr | RASf);
|
||||
output nCAS0 = ~(CAS0f | (CASr & RAMSEL & ~Addr[22])); // DRAM CAS bank 0
|
||||
output nCAS1 = ~(CAS1f | (CASr & RAMSEL & Addr[22])); // DRAM CAS bank 1
|
||||
|
||||
/* 6502-accessible Registers */
|
||||
reg REGEN = 0; // Register enable
|
||||
reg IOROMEN = 0; // IOSTRB ROM enable
|
||||
reg FullIOEN = 0; // Set to enable full I/O ROM space
|
||||
reg PDMARDEN = 0;
|
||||
reg PDMAWREN = 0;
|
||||
reg [7:0] Bank = 0; // Bank register for ROM access
|
||||
reg [23:0] Addr = 0; // RAM address register
|
||||
|
||||
/* RAM Address Register Increment Control */
|
||||
reg IncAddrL = 0, IncAddrM = 0, IncAddrH = 0;
|
||||
|
||||
/* Pseudo-DMA Transfer Counters */
|
||||
reg [9:0] TCnt = 0;
|
||||
reg [15:0] Dest = 0;
|
||||
|
||||
/* Transfer Counter Increment Control */
|
||||
reg PDMANext = 0, IncDestH = 0;
|
||||
|
||||
/* CAS rising/falling edge components */
|
||||
// These are combined to create the CAS outputs.
|
||||
reg CASr = 0, CAS0f = 0, CAS1f = 0;
|
||||
reg RASr = 0, RASf = 0;
|
||||
reg CASel = 0; // DRAM address multiplexer select
|
||||
|
||||
/* State Counters */
|
||||
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
|
||||
reg DBEN = 0; // Data bus driver gating
|
||||
reg CSEN = 0; // ROM CS enable gating
|
||||
|
||||
/* Configuration */
|
||||
input Mode;
|
||||
|
||||
// Apple II Bus Compatibiltiy Rules:
|
||||
// Synchronize to PHI0 or PHI1. (PHI1 here)
|
||||
// PHI1's edge may be -20ns,+10ns relative to C7M.
|
||||
// Delay the rising edge of PHI1 to get enough hold time:
|
||||
// PHI1modified = PHI1 & PHI1delayed;
|
||||
// Only sample /DEVSEL, /IOSEL at these times:
|
||||
// 2nd and 3rd rising edge of C7M in PHI0 (S4, S5)
|
||||
// all 3 falling edges of C7M in PHI0 (S4, S5, S6)
|
||||
// Can sample /IOSTRB at same times as /IOSEL, plus:
|
||||
// 1st rising edge of C7M in PHI0 (S3)
|
||||
|
||||
/* State counters */
|
||||
always @(posedge C7M) begin
|
||||
// Synchronize state counter to S1 when just entering PHI1
|
||||
PHI1reg <= PHI1; // Save old PHI1
|
||||
if (~PHI1) PHI0seen <= 1; // PHI0seen set in PHI0
|
||||
S <= (PHI1 & ~PHI1reg & PHI0seen) ? 4'h1 :
|
||||
S==0 ? 3'h0 :
|
||||
S==7 ? 3'h7 : S+1;
|
||||
|
||||
// Refresh counter allows DRAM refresh once every 13 cycles
|
||||
if (S==3) Ref <= (Ref[3:2]==2'b11) ? 4'h0 : Ref+1;
|
||||
/* Reset inputs */
|
||||
input nRST, nPreBOD;
|
||||
reg nRSTr0;
|
||||
always @(posedge C25M) begin
|
||||
nRSTr0 <= nRST;
|
||||
end
|
||||
|
||||
/* State-based data bus and ROM CS gating */
|
||||
always @(posedge C7M, negedge nRES) begin
|
||||
if (~nRES) begin
|
||||
DBEN <= 0;
|
||||
CSEN <= 0;
|
||||
end else begin
|
||||
// Only drive Apple II data bus after S4 to avoid bus fight.
|
||||
// Thus we wait 1.5 7M cycles (210 ns) into PHI0 before driving.
|
||||
// Same for driving the ROM/SRAM data bus (RD).
|
||||
DBEN <= S==4 | S==5 | S==6 | S==7;
|
||||
|
||||
// Similarly, only select the ROM chip starting at
|
||||
// the end of S4 for reads and the end of S5 for writes.
|
||||
// This ensures that write data is valid for
|
||||
// the entire time that the ROM is selected,
|
||||
// and minimizes power consumption.
|
||||
CSEN <= (S==4 & nWE) | S==5 | S==6 | S==7;
|
||||
end
|
||||
/* Select inputs */
|
||||
input nIOSEL, nDEVSEL, nIOSTRB;
|
||||
/* Synchronized select inputs */
|
||||
reg nDEVSELr0, nDEVSELr1;
|
||||
reg nIOSELr0;
|
||||
reg nIOSTRBr0;
|
||||
always @(posedge C25M) begin
|
||||
nDEVSELr0 <= nDEVSEL;
|
||||
nDEVSELr1 <= nDEVSELr0;
|
||||
nIOSELr0 <= nIOSEL;
|
||||
nIOSTRBr0 <= nIOSTRB;
|
||||
end
|
||||
/* DEVSEL-based state counter */
|
||||
wire [9:0] DEVSELe = {DEVSELer[9:1], nDEVSELr1 && ~nDEVSELr0 && nRSTr0}
|
||||
reg [9:1] DEVSELer;
|
||||
always @(posedge C25M) begin
|
||||
DEVSELer[9:1] <= DEVSELe[8:0];
|
||||
end
|
||||
|
||||
/* DEVSEL register and IOSTRB ROM enable */
|
||||
always @(posedge C7M, negedge nRES) begin
|
||||
if (~nRES) begin
|
||||
REGEN <= 0;
|
||||
IOROMEN <= 0;
|
||||
end else begin
|
||||
// Enable registers at end of S4 when IOSEL accessed (Cn00-CnFF).
|
||||
if (S==4 & ~nIOSEL) REGEN <= 1'b1;
|
||||
/* Flash Control */
|
||||
output nRCS = ~((~nIOSEL || (~nIOSTRB && IOROMEN)) && CSDBEN && nRST);
|
||||
output nROE = ~nRWE;
|
||||
|
||||
// Enable IOSTRB ROM when accessing CnXX in IOSEL ROM.
|
||||
if (S==4 & ~nIOSEL) IOROMEN <= 1'b1;
|
||||
// Disable IOSTRB ROM when accessing 0xCFFF.
|
||||
if (S==4 & ~nIOSTRB & A[10:0]==11'h7FF) IOROMEN <= 1'b0;
|
||||
end
|
||||
/* 6502/Flash Data Bus */
|
||||
inout RD = RDOE ? Rdout : 8'bZ;
|
||||
wire RDOE = ~nDEVSEL && nRST;
|
||||
wire RDout =
|
||||
AddrLSelA ? Addr[7:0] :
|
||||
AddrMSelA ? Addr[15:8] :
|
||||
AddrHSelA ? Addr[23:16] :
|
||||
DataSelA ? Addr==0 ? Data0[7:0] : Data[7:0] :
|
||||
8'h57;
|
||||
output nDOE = ~((~nDEVSEL || ~nIOSEL || (~nIOSTRB && IOROMEN)) && CSDBEN && nRST);
|
||||
output Ddir = ~nRWE;
|
||||
|
||||
/* Data bus / ROM chip select delay */
|
||||
reg CSDBEN = 0;
|
||||
always @(posedge C25M, negedge nRST) begin
|
||||
if (~nRST) CSDBEN <= 1'b0;
|
||||
else CSDBEN <= ~nDEVSELr0 || ~nIOSELr0 || ~nIOSTRBr0;
|
||||
end
|
||||
|
||||
/* Set registers */
|
||||
always @(negedge C7M, negedge nRES) begin
|
||||
if (~nRES) begin
|
||||
|
||||
/* IOROMEN control */
|
||||
wire IOROMEN = IOROMEN0 ^ IOROMEN1;
|
||||
reg IOROMEN0 = 0;
|
||||
reg IOROMEN1 = 0;
|
||||
always @(negedge nIOSEL, negedge nRST) begin
|
||||
if (~nRST) IOROMEN0 <= 1'b0; // On reset, set both to 0; 0 ^ 0 == 0
|
||||
else IOROMEN0 <= ~IOROMEN1; // Enable; X ^ ~X == 1
|
||||
end
|
||||
always @(negedge nIOSTRB, negedge nRST) begin
|
||||
if (~nRST) IOROMEN1 <= 1'b0; // On reset, set both to 0; 0 ^ 0 == 0
|
||||
else if (RA[10:0] == 11'h7FF) IOROMEN1 <= IOROMEN0; // Disable; X^X==0
|
||||
end
|
||||
|
||||
/* 6502/Flash Address Bus */
|
||||
input [15:0] RA;
|
||||
input nRWE;
|
||||
output nAOE = 0;
|
||||
output Adir = 1;
|
||||
reg [3:0] RAr;
|
||||
reg nRWEr;
|
||||
always @(posedge nDEVSEL) begin
|
||||
// Latch RA and nRWE at end of DEVSEL access
|
||||
RAr[3:0] <= RA[3:0];
|
||||
nRWEr <= nRWE;
|
||||
end
|
||||
|
||||
/* Register Select Signals */
|
||||
wire AddrLSelA = RA[3:0] == 4'h0;
|
||||
wire AddrMSelA = RA[3:0] == 4'h1;
|
||||
wire AddrHSelA = RA[3:0] == 4'h2;
|
||||
wire DataSelA = RA[3:0] == 4'h3;
|
||||
wire DMAAddrLSelA = RA[3:0] == 4'h4;
|
||||
wire DMAAddrHSelA = RA[3:0] == 4'h5;
|
||||
wire DMALenLSelA = RA[3:0] == 4'h6;
|
||||
wire DMALenHSelA = RA[3:0] == 4'h7;
|
||||
|
||||
wire MagicSelA = RA[3:0] == 4'h8;
|
||||
wire CfgSelA = RA[3:0] == 4'h9;
|
||||
wire RAMMaskSelA = RA[3:0] == 4'hB;
|
||||
wire BankHSelA = RA[3:0] == 4'hE;
|
||||
wire BankLSelA = RA[3:0] == 4'hF;
|
||||
|
||||
/* SDRAM Address / Flash Bank Bus */
|
||||
output [1:0] SBA = SAmux ? SBAreg[1:0] :
|
||||
~nIOSTRB ? {
|
||||
BankC8[4], // SBA0, Bank4
|
||||
BankC8[2] // SBA1, Bank2
|
||||
} : { // IOSEL
|
||||
1'b1, // SBA0, Bank4
|
||||
1'b1 // SBA1, Bank2
|
||||
};
|
||||
output [12:0] SA = SAmux ? SAreg[12:0] :
|
||||
~nIOSTRB ? {
|
||||
SAreg[0], // SA0
|
||||
BankC8[11], // SA1, Bank11
|
||||
BankC8[8] ^ BankCX[8], // SA2, Bank8
|
||||
SAreg[3], // SA3
|
||||
SAreg[4], // SA4
|
||||
ExtBankEN ? BankC8[7] : 1'b0, // SA5, Bank7
|
||||
SAreg[6], // SA6
|
||||
BankC8[10], // SA7, Bank10
|
||||
BankC8[9] ^ BankCX[9], // SA8, Bank9
|
||||
BankC8[1], // SA9, Bank1
|
||||
BankC8[0], // SA10, Bank0
|
||||
BankC8[3], // SA11, Bank3
|
||||
BankC8[5] // SA12, Bank5
|
||||
} : { // IOSEL
|
||||
SAreg[0], // SA0
|
||||
1'b0, // SA1, Bank11
|
||||
BankCX[8], // SA2, Bank8
|
||||
SAreg[3], // SA3
|
||||
SAreg[4], // SA4
|
||||
1'b1, // SA5, Bank7
|
||||
SAreg[6], // SA6
|
||||
1'b0, // SA7, Bank10
|
||||
BankCX[9], // SA8, Bank9
|
||||
1'b1, // SA9, Bank1
|
||||
1'b1, // SA10, Bank0
|
||||
1'b1, // SA11, Bank3
|
||||
1'b1 // SA12, Bank5
|
||||
};
|
||||
output RB6 = ~nIOSEL ? 1'b1 : BankC8[6];
|
||||
reg SAmux = 1'b0;
|
||||
reg [1:0] SBAreg;
|
||||
reg [12:0] SAreg;
|
||||
|
||||
/* SDRAM Data Bus */
|
||||
inout [7:0] SD = SDOE ? WRD : 8'bZ;
|
||||
reg SDOE = 0;
|
||||
reg [7:0] WRD = 0;
|
||||
always @(posedge nDEVSEL) begin
|
||||
WRD[7:0] <= RD[7:0];
|
||||
if (nRSTr0 && DataSelA && ~nRWE && Addr==0) Data0[7:0] <= RD[7:0];
|
||||
end
|
||||
|
||||
/* SDRAM Control Bus */
|
||||
output reg nSCS = 1;
|
||||
output reg nRAS = 1;
|
||||
output reg nCAS = 1;
|
||||
output reg nSWE = 1;
|
||||
output reg DQML = 1;
|
||||
output reg DQMH = 1;
|
||||
output reg SCKE = 1;
|
||||
|
||||
/* INT/DMA in/out */
|
||||
input DMAin;
|
||||
input INTin;
|
||||
output DMAout = DMAin;
|
||||
output INTout = INTin;
|
||||
|
||||
/* IRQ, NMI, DMA, INH outputs (open-drain is external) */
|
||||
output nIRQ = 1;
|
||||
output nNMI = 1;
|
||||
output nDMA = 1;
|
||||
output nINH = 1;
|
||||
|
||||
/* Refresh/Init Counter */
|
||||
reg [19:0] Tick;
|
||||
always @(posedge C25M) begin
|
||||
Tick <= Tick+1;
|
||||
end
|
||||
reg InitDone = 0;
|
||||
always @(posedge C25M) begin
|
||||
if (Tick[19:0]==20'hFFFFF) InitDone <= 1'b1;
|
||||
end
|
||||
reg RefWake = 0;
|
||||
reg RefDone = 0;
|
||||
|
||||
/* User-Accessible Registers */
|
||||
reg [23:0] Addr = 0;
|
||||
reg [7:0] Data = 0;
|
||||
reg [7:0] Data0 = 0;
|
||||
reg [11:0] BankC8 = 0; // Bits 9:8 are XORed with BankCX
|
||||
reg [9:8] BankCX = 0; // Bank CX is init value
|
||||
reg ExtBankEN = 0;
|
||||
|
||||
/* Set/Increment Address Register */
|
||||
always @(posedge C25M, negedge nRST) begin
|
||||
if (~nRST) begin
|
||||
Addr <= 0;
|
||||
Bank <= 0;
|
||||
FullIOEN <= 0;
|
||||
PDMARDEN <= 0;
|
||||
PDMAWREN <= 0;
|
||||
IncAddrL <= 0;
|
||||
IncAddrM <= 0;
|
||||
IncAddrH <= 0;
|
||||
end else begin
|
||||
// Increment address register
|
||||
if (S==1 & IncAddrL) begin
|
||||
IncAddrL <= 0;
|
||||
Addr[7:0] <= Addr[7:0]+1;
|
||||
IncAddrM <= Addr[7:0] == 8'hFF;
|
||||
end
|
||||
if (S==2 & IncAddrM) begin
|
||||
IncAddrM <= 0;
|
||||
Addr[15:8] <= Addr[15:8]+1;
|
||||
IncAddrH <= Addr[15:8] == 8'hFF;
|
||||
end
|
||||
if (S==3 & IncAddrH) begin
|
||||
IncAddrH <= 0;
|
||||
Addr[23:16] <= Addr[23:16]+1;
|
||||
end
|
||||
|
||||
// Set register in middle of S6 if accessed.
|
||||
if (S==6) begin
|
||||
if (BankWR) begin
|
||||
Bank[7:0] <= D[7:0];
|
||||
PDMARDEN <= D[7:0]==8'h10 & FullIOEN;
|
||||
PDMAWREN <= D[7:0]==8'h10 & FullIOEN;
|
||||
if (DEVSELe[0] && ~nRWEr) begin // Write address register
|
||||
if (RAr[3:0]==4'h0) begin // AddrL
|
||||
Addr[7:0] <= WRD[7:0];
|
||||
if (Addr[7] & ~WRD[7]) Addr[23:8] <= Addr[23:8]+1;
|
||||
end else if (RAr[3:0]==4'h1) begin // AddrM
|
||||
Addr[15:8] <= WRD[7:0];
|
||||
if (Addr[15] & ~WRD[7]) Addr[23:16] <= Addr[23:16]+1;
|
||||
end else if (RAr[3:0]==4'h2) begin // AddrH
|
||||
Addr[23:16] <= WRD[7:0];
|
||||
end
|
||||
if (MagicWR) FullIOEN <= D[7:0] == 8'hE5;
|
||||
|
||||
IncAddrL <= RAMSEL;
|
||||
IncAddrM <= AddrLWR & Addr[7] & ~D[7];
|
||||
IncAddrH <= AddrMWR & Addr[15] & ~D[7];
|
||||
|
||||
if (AddrHWR) Addr[23:16] <= D[7:0]; // Addr hi
|
||||
if (AddrMWR) Addr[15:8] <= D[7:0]; // Addr mid
|
||||
if (AddrLWR) Addr[7:0] <= D[7:0]; // Addr lo
|
||||
end else if (DEVSELe[2] && RAr[3:0]==4'h3) begin // R/W data
|
||||
Addr[23:0] <= Addr[23:0]+1;
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
/* Pseudo-DMA transfer counters */
|
||||
always @(negedge C7M, negedge nRES) begin
|
||||
if (~nRES) begin
|
||||
TCnt <= 0;
|
||||
Dest <= 0;
|
||||
PDMANext <= 0;
|
||||
IncDestH <= 0;
|
||||
/* Set bank */
|
||||
always @(posedge nDEVSEL, negedge nRST) begin
|
||||
if (~nRST) begin
|
||||
BankC8 <= 0;
|
||||
end else begin
|
||||
// Increment destination pointer and decrement transfer counter
|
||||
if (S==1 & PDMANext) begin
|
||||
PDMANext <= 0;
|
||||
Dest[7:0] <= Dest[7:0]+1;
|
||||
IncDestH <= Dest[7:0] == 8'hFF;
|
||||
TCnt <= TCnt-1;
|
||||
end
|
||||
if (S==2 & IncDestH) begin
|
||||
IncDestH <= 0;
|
||||
Dest[15:8] <= Dest[15:8]+1;
|
||||
end
|
||||
|
||||
// Set register in middle of S6 if accessed.
|
||||
if (S==6) begin
|
||||
PDMANext <= RAMSEL;
|
||||
|
||||
if (TCntHWR) TCnt[15:8] <= D[7:0]; // TCnt hi
|
||||
if (TCntLWR) TCnt[7:0] <= D[7:0]; // TCnt lo
|
||||
if (DestHWR) Dest[15:8] <= D[7:0]; // Dest hi
|
||||
if (DestLWR) Dest[7:0] <= D[7:0]; // Dest lo
|
||||
if (~nRWE) begin
|
||||
if (RAr[3:0]==4'hE && ExtBankEN) begin
|
||||
BankC8[11:10] <= WRD[3:2];
|
||||
BankC8[9:8] <= WRD[1:0] ^ BankCX[9:8];
|
||||
end else if (RAr[3:0]==4'hF) begin
|
||||
BankC8[7] <= WRD[7] & ExtBankEN;
|
||||
BankC8[6:0] <= WRD[6:0];
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
/* DRAM RAS/CAS */
|
||||
always @(posedge C7M) begin
|
||||
RASr <= (S==1 & Ref==0) | // Refresh
|
||||
(S==4 & RAMSEL & nWE) | // Read: Early RAS
|
||||
(S==5 & RAMSEL & ~nWE); // Write: Late RAS
|
||||
CASel = (RAMSEL & nWE & S==4) | // Read: mux address early
|
||||
(RAMSEL & ~nWE & S==5); // Write: mux address late
|
||||
// Read: long, early CAS, gated later by RAMSEL
|
||||
CASr <= (nWE & (S==5 | S==6 | S==7));
|
||||
/* Latch read data */
|
||||
always @(posedge C25M) begin
|
||||
if (DEVSELe[9]) Data[7:0] <= SDD[7:0];
|
||||
end
|
||||
always @(negedge C7M) begin
|
||||
RASf <= (S==4 & RAMSEL & nWE) | // Read: Early RAS
|
||||
(S==5 & RAMSEL & ~nWE); // Write: Late RAS
|
||||
CAS0f <= (S==1 & Ref==0) | // Refresh
|
||||
(S==5 & RAMSEL & ~Addr[22] & nWE) | // Read: Early CAS
|
||||
(S==6 & RAMSEL & ~Addr[22] & ~nWE); // Write: Late CAS
|
||||
CAS1f <= (S==1 & Ref==0) | // Refresh
|
||||
(S==5 & RAMSEL & Addr[22] & nWE) | // Read: Early CAS
|
||||
(S==6 & RAMSEL & Addr[22] & ~nWE); // Write: Late CAS
|
||||
|
||||
/* SDRAM Control */
|
||||
always @(posedge C25M) begin
|
||||
if (~InitDone) begin
|
||||
if (Tick[19:8]==12'hFFF) begin
|
||||
if (Tick[3:0]==4'h8) begin
|
||||
if (Tick[7:4]==4'h0) begin
|
||||
// PC all
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b0;
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b0;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAreg[10] <= 1'b1; // "all"
|
||||
end else if (Tick[7:4]==4'h7) begin
|
||||
// Load mode register
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b0;
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b0;
|
||||
nSWE <= 1'b0;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAreg[11] <= 1'b0; // Reserved in mode register
|
||||
end else begin
|
||||
// AREF
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b0;
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b0;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
end
|
||||
end else begin
|
||||
// NOP
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
end
|
||||
end else begin
|
||||
// NOP ckdis
|
||||
SCKE <= 1'b0;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
end
|
||||
|
||||
// Mode register contents
|
||||
SBAreg[1:0] <= 2'b00; // Reserved
|
||||
SAreg[11] <= 1'b0; // Reserved
|
||||
SAreg[9] <= 1'b1; // "1" for single write mode
|
||||
SAreg[8] <= 1'b0; // Reserved
|
||||
SAreg[7] <= 1'b0; // "0" for not test mode
|
||||
SAreg[6:4] <= 3'b010; // "2" for CAS latency 2
|
||||
SAreg[3] <= 1'b0; // "0" for sequential burst (not used)
|
||||
SAreg[2:0] <= 3'b000; // "0" for burst length 1 (no burst)
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefDone <= 1'b0;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[0] && RAr[3:0]==4'h3) begin
|
||||
// NOP
|
||||
SCKE <= ~nRWEr;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[1] && RAr[3:0]==4'h3) begin
|
||||
// ACT
|
||||
SCKE <= ~nRWEr;
|
||||
nSCS <= nRWEr;
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
// Row address
|
||||
SBAreg[1:0] <= Addr[23:22];
|
||||
SAreg[12] <= 1'b0;
|
||||
SAreg[11:0] <= Addr[21:10];
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[2] && RAr[3:0]==4'h3) begin
|
||||
// WR/NOP
|
||||
SCKE <= ~nRWEr;
|
||||
nSCS <= nRWEr;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b0;
|
||||
nSWE <= 1'b0;
|
||||
DQML <= Addr[0];
|
||||
DQMH <= ~Addr[0];
|
||||
|
||||
// Column address
|
||||
SBAreg[1:0] <= Addr[23:22];
|
||||
SAreg[12:11] <= 2'b00;
|
||||
SAreg[9] <= 1'b0;
|
||||
SAreg[8:0] <= Addr[9:1];
|
||||
|
||||
// Auto-precharge only if row will increment
|
||||
SAreg[10] <= Addr[9:0]==10'h3FF;
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[3] && RAr[3:0]==4'h3) begin
|
||||
// NOP
|
||||
SCKE <= ~nRWEr;
|
||||
nSCS <= nRWEr;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAmux <= 1'b0;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[4] && RAr[3:0]==4'h3) begin
|
||||
// NOP (auto-precharge from previous write)
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAmux <= 1'b0;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[5] && RAr[3:0]==4'h3) begin
|
||||
// ACT only if WR AP just occurred / NOP
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= ~nRWEr && ~SAreg[10];
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
// Row address
|
||||
SBAreg[1:0] <= Addr[23:22];
|
||||
SAreg[12] <= 1'b0;
|
||||
SAreg[11:0] <= Addr[21:10];
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[6] && RAr[3:0]==4'h3) begin
|
||||
// RD
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b0;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b0;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= Addr[0];
|
||||
DQMH <= ~Addr[0];
|
||||
|
||||
// Column address
|
||||
SBAreg[1:0] <= Addr[23:22];
|
||||
SAreg[12:11] <= 2'b00;
|
||||
SAreg[10] <= 1'b1; // auto-precharge
|
||||
SAreg[9] <= 1'b0;
|
||||
SAreg[8:0] <= Addr[9:1];
|
||||
|
||||
SAmux <= 1'b1;
|
||||
RefWake <= 1'b0;
|
||||
end else if (DEVSELe[7] && RAr[3:0]==4'h3) begin
|
||||
// NOP
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
SAmux <= 1'b0;
|
||||
RefWake <= 1'b0;
|
||||
end else begin
|
||||
if (Tick[5] && ~RefDone) begin
|
||||
if (~RefWake) begin
|
||||
// NOP
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
RefWake <= 1'b1;
|
||||
end else begin
|
||||
// AREF
|
||||
SCKE <= 1'b1;
|
||||
nSCS <= 1'b0;
|
||||
nRAS <= 1'b0;
|
||||
nCAS <= 1'b0;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
RefWake <= 1'b0;
|
||||
RefDone <= 1'b1;
|
||||
end
|
||||
end else begin
|
||||
// NOP ckdis
|
||||
SCKE <= 1'b0;
|
||||
nSCS <= 1'b1;
|
||||
nRAS <= 1'b1;
|
||||
nCAS <= 1'b1;
|
||||
nSWE <= 1'b1;
|
||||
DQML <= 1'b1;
|
||||
DQMH <= 1'b1;
|
||||
|
||||
RefWake <= 1'b0;
|
||||
if (Tick[5]) RefDone <= 1'b0;
|
||||
end
|
||||
|
||||
SAmux <= 1'b0;
|
||||
end
|
||||
end
|
||||
endmodule
|
||||
|
||||
/* UFM Interface */
|
||||
reg ARCLK = 0; // UFM address register clock
|
||||
// UFM address register data input tied to 0
|
||||
reg ARShift = 0; // 1 to Shift UFM address in, 0 to increment
|
||||
reg DRCLK = 0; // UFM data register clock
|
||||
reg DRDIn = 0; // UFM data register input
|
||||
reg DRShift = 0; // 1 to shift UFM out, 0 to load from current address
|
||||
reg UFMErase = 0; // Rising edge starts erase. UFM+RTP must not be busy
|
||||
reg UFMProgram = 0; // Rising edge starts program. UFM+RTP must not be busy
|
||||
wire UFMBusy; // 1 if UFM is doing user operation. Asynchronous
|
||||
wire RTPBusy; // 1 if real-time programming in progress. Asynchronous
|
||||
wire DRDOut; // UFM data output
|
||||
// UFM oscillator always enabled
|
||||
wire UFMOsc; // UFM oscillator output (3.3-5.5 MHz)
|
||||
UFM UFM_inst ( // UFM IP block (for Altera MAX II and MAX V)
|
||||
.arclk (ARCLK),
|
||||
.ardin (1'b0),
|
||||
.arshft (ARShift),
|
||||
.drclk (DRCLK),
|
||||
.drdin (DRDIn),
|
||||
.drshft (DRShift),
|
||||
.erase (UFMErase),
|
||||
.oscena (1'b1),
|
||||
.program (UFMProgram),
|
||||
.busy (UFMBusy),
|
||||
.drdout (DRDOut),
|
||||
.osc (UFMOsc),
|
||||
.rtpbusy (RTPBusy));
|
||||
reg UFMBr = 0; // UFMBusy registered to sync with C14M
|
||||
reg RTPBr = 0; // RTPBusy registered to sync with C14M
|
||||
|
||||
reg [15:0] Cfg;
|
||||
reg CfgLoaded = 0;
|
||||
// Do nothing when Tick15:14==2'h0
|
||||
// Get ready when Tick15:14==2'h1
|
||||
// Zero AR
|
||||
// Load Cfg when Tick15:14==2'h2
|
||||
// Tick13:6 (256) - first half of UFM looked at
|
||||
// Tick5:2 (16) - 16 bits loaded from UFM
|
||||
// 0: set CfgLoaded if DRDout==1, otherwise shift DRDout into Cfg
|
||||
// 1-14: continue shifting DRDout into Cfg[15:0]
|
||||
// 15: shift last DRDout bit into Cfg[15:0] and increment AR
|
||||
// Tick1:0 (4) - 1 bit shifted
|
||||
// Do nothing when Tick15:14==2'h3
|
||||
// Set CfgLoaded too
|
||||
always @(posedge C25M) begin
|
||||
if (~CfgLoaded) begin
|
||||
if (Tick[15:14]==2'h0) begin
|
||||
// Do nothing
|
||||
ARShift <= 1;
|
||||
ARCLK <= 0;
|
||||
DRCLK <= 0;
|
||||
end else if (Tick[15:14]==2'h1) begin
|
||||
// Shift zeros into AR during first half
|
||||
if (~Tick[13]) begin
|
||||
ARShift <= 1;
|
||||
ARCLK <= Tick[1];
|
||||
end else begin
|
||||
ARShift <= 0;
|
||||
ARCLK <= 0;
|
||||
end
|
||||
|
||||
// Load default config
|
||||
Cfg[15:0] <= 16'hFFFF;
|
||||
|
||||
// Load indirect into DR at end
|
||||
if (Tick[13:0]==14'h3FFC ||
|
||||
Tick[13:0]==14'h3FFD ||
|
||||
Tick[13:0]==14'h3FFE ||
|
||||
Tick[13:0]==14'h3FFF || ) begin
|
||||
DRCLK <= 1;
|
||||
end else DRCLK <= 0;
|
||||
end else if (Tick[15:14]==2'h2) begin
|
||||
// Load 16 bits into Cfg register
|
||||
if (Tick[5:2]==4'h0 && Tick[1:0]==0 && DRDout) begin
|
||||
CfgLoaded <= 1;
|
||||
end else if (Tick[1:0]==0) begin
|
||||
Cfg[15:0] <= {Cfg[14:1], DRDout};
|
||||
end
|
||||
|
||||
// Increment AR
|
||||
if (Tick[5:2]==4'hE) begin
|
||||
ARCLK <= 1;
|
||||
end else begin
|
||||
ARCLK <= 0;
|
||||
end
|
||||
|
||||
// Load indirect into DR
|
||||
if (Tick[5:2]==4'hF) begin
|
||||
DRCLK <= 1;
|
||||
end else begin
|
||||
DRCLK <= 0;
|
||||
end
|
||||
|
||||
ARShift <= 1'b0; // Only incrementing AR now
|
||||
end else if (Tick[15:14]==2'h3) begin
|
||||
// Do nothing
|
||||
ARShift <= 1;
|
||||
ARCLK <= 0;
|
||||
DRCLK <= 0;
|
||||
CfgLoaded <= 1; // in case setting at address 0xFF
|
||||
end
|
||||
|
||||
DRShift <= 0; // Only reading DR during init, not writing UFM
|
||||
DRDIn <= 0;
|
||||
end else if (DEVSELe[0] && RAr[3:0]==4'h8) begin
|
||||
|
||||
end else begin
|
||||
// Do nothing
|
||||
ARShift <= 1;
|
||||
ARCLK <= 0;
|
||||
DRCLK <= 0;
|
||||
DRShift <= 0;
|
||||
DRDIn <= 0;
|
||||
end
|
||||
end
|
||||
|
||||
|
||||
always @(posedge nDEVSEL, negedge nRST) begin
|
||||
if (~nRST)
|
||||
end
|
||||
endmodule
|
||||
|
||||
Loading…
Reference in New Issue
Block a user