nextpnr/generic/synth/prims.v
David Shah f88ddf85b2 generic: Add simple primitive library
Signed-off-by: David Shah <dave@ds0.me>
2019-04-02 15:30:01 +01:00

59 lines
948 B
Verilog

// LUT and DFF are combined to a GENERIC_SLICE
module LUT #(
parameter K = 4,
parameter [2**K-1:0] INIT = 0,
) (
input [K-1:0] I,
output Q
);
assign Q = INIT[I];
endmodule
module DFF (
input CLK, D,
output reg Q
);
always @(posedge CLK)
Q <= D;
endmodule
module GENERIC_SLICE #(
parameter K = 4,
parameter [2**K-1:0] INIT = 0,
parameter FF_USED = 1'b0
) (
input CLK,
input [K-1:0] I,
output Q
);
wire lut_q;
LUT #(.K(K), .INIT(INIT)) lut_i(.I(I), .Q(lut_q));
generate if (FF_USED)
DFF dff_i(.CLK(CLK), .D(lut_q), .Q(Q));
else
assign Q = lut_q;
endgenerate
endmodule
module GENERIC_IOB #(
parameter INPUT_USED = 1'b0,
parameter OUTPUT_USED = 1'b0,
parameter ENABLE_USED = 1'b0
) (
inout PAD,
input I, EN,
output O
);
generate if (OUTPUT_USED && ENABLE_USED)
assign PAD = EN ? I : 1'bz;
else if (OUTPUT_USED)
assign PAD = I;
endgenerate
generate if (INPUT_USED)
assign O = PAD;
endgenerate
endmodule