OpenFPGA/openfpga_flow/openfpga_cell_library/verilog/sram.v

397 lines
9.9 KiB
Verilog

//-----------------------------------------------------
// Design Name : sram_blwl
// File Name : sram.v
// Coder : Xifan TANG
//-----------------------------------------------------
//-----------------------------------------------------
// Function : A SRAM cell with write enable
//-----------------------------------------------------
module SRAM(
input WE, // Word line control signal as write enable
input D, // Bit line control signal
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(WE or D)
begin
if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-high set
// - a write-enable
//-----------------------------------------------------
module SRAMS(
input SET, // active-high set signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b1 == SET) begin
data <= 1'b1;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-low set
// - a write-enable
//-----------------------------------------------------
module SRAMSN(
input SETN, // active-low set signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b0 == SETN) begin
data <= 1'b1;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-high reset
// - a write-enable
//-----------------------------------------------------
module SRAMR(
input RST, // active-high reset signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b1 == RST) begin
data <= 1'b0;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-low reset
// - a write-enable
//-----------------------------------------------------
module SRAMRN(
input RSTN, // active-low reset signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b0 == RSTN) begin
data <= 1'b0;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-high reset
// - an active-high set
// - a write-enable
//-----------------------------------------------------
module SRAMSR(
input RST, // active-high reset signal
input SET, // active-high set signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b1 == RST) begin
data <= 1'b0;
end else if (1'b1 == SET) begin
data <= 1'b1;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with WL read signal
//-----------------------------------------------------
module SRAM_RE(
input WE, // Word line control signal as write enable
input RE, // Word line read signal as read enable
inout D, // Bit line control signal
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
reg data_readback;
//----- when wl is enabled, we can read in data from bl
always @(WE or RE or D)
begin
if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
endmodule
//-----------------------------------------------------
// Function : A SRAM cell with
// - an active-low reset
// - an active-low set
// - a write-enable
//-----------------------------------------------------
module SRAMSNRN(
input RSTN, // active-low reset signal
input SETN, // active-low set signal
input WE, // Word line control signal as write enable
input D, // Bit line control signal as data input
output Q, // Data output
output QN // Data output
);
//----- local variable need to be registered
reg data;
//----- when wl is enabled, we can read in data from bl
always @(D or WE)
begin
if (1'b0 == RSTN) begin
data <= 1'b0;
end else if (1'b0 == SETN) begin
data <= 1'b1;
end else if ((1'b1 == D)&&(1'b1 == WE)) begin
//----- Cases to program internal memory bit
//----- case 1: bl = 1, wl = 1, a -> 0
data <= 1'b1;
end else if ((1'b0 == D)&&(1'b1 == WE)) begin
//----- case 2: bl = 0, wl = 1, a -> 0
data <= 1'b0;
end
end
`ifndef ENABLE_FORMAL_VERIFICATION
// Wire q_reg to Q
assign Q = data;
assign QN = ~data;
`else
assign Q = 1'bZ;
assign QN = !Q;
`endif
endmodule
module sram6T_rram(
input read,
input nequalize,
input din, // Data input
output dout, // Data output
output doutb, // Data output
// !!! Port bit position should start from LSB to MSB
// Follow this convention for BL/WLs in each module!
input [0:2] bl, // Bit line control signal
input [0:2] wl// Word line control signal
);
//----- local variable need to be registered
//----- Modeling two RRAMs
reg r0, r1;
always @(bl[0], wl[2])
begin
//----- Cases to program r0
//----- case 1: bl[0] = 1, wl[2] = 1, r0 -> 0
if ((1'b1 == bl[0])&&(1'b1 == wl[2])) begin
r0 <= 0;
end
end
always @(bl[2], wl[0])
begin
//----- case 2: bl[2] = 1, wl[0] = 1, r0 -> 1
if ((1'b1 == bl[2])&&(1'b1 == wl[0])) begin
r0 <= 1;
end
end
always @(bl[1], wl[2])
begin
//----- Cases to program r1
//----- case 1: bl[1] = 1, wl[2] = 1, r0 -> 0
if ((1'b1 == bl[1])&&(1'b1 == wl[2])) begin
r1 <= 0;
end
end
always @( bl[2], wl[1])
begin
//----- case 2: bl[2] = 1, wl[1] = 1, r0 -> 1
if ((1'b1 == bl[2])&&(1'b1 == wl[1])) begin
r1 <= 1;
end
end
// dout is r0 AND r1
assign dout = r0 | (~r1);
//---- doutb is always opposite to dout
assign doutb = ~dout;
endmodule