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|
# Bad case: independent write ports.
read_verilog << EOT
module top(
input [3:0] wa1, wa2, ra, wd1, wd2,
input clk, we1, we2,
output [3:0] rd);
reg [3:0] mem[0:15];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1)
mem[wa1] <= wd1;
if (we2)
mem[wa2] <= wd2;
end
endmodule
EOT
hierarchy -auto-top
proc
opt
memory -nomap
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=4'b0100 %i
design -reset
# Good case: write ports with definitely different addresses.
read_verilog << EOT
module top(
input [3:0] wa, ra, wd1, wd2,
input clk, we1, we2,
output [3:0] rd);
reg [3:0] mem[0:15];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1)
mem[wa] <= wd1;
if (we2)
mem[wa ^ 1] <= wd2;
end
endmodule
EOT
hierarchy -auto-top
proc
opt
memory -nomap
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=4'b0000 %i
design -reset
# Bad case 2: the above, but broken.
read_verilog << EOT
module top(
input [3:0] wa, ra, wd1, wd2,
input clk, we1, we2,
output [3:0] rd);
reg [3:0] mem[0:15];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1)
mem[wa] <= wd1;
if (we2)
mem[wa | 1] <= wd2;
end
endmodule
EOT
hierarchy -auto-top
proc
opt
memory -nomap
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=4'b0100 %i
design -reset
# Good case 2: write ports with disjoint bit enables.
read_verilog << EOT
module top(
input [3:0] wa1, wa2, ra,
input [1:0] wd1, wd2,
input clk, we1, we2,
output [3:0] rd);
reg [3:0] mem[0:15];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1)
mem[wa1][1:0] <= wd1;
if (we2)
mem[wa2][3:2] <= wd2;
end
endmodule
EOT
hierarchy -auto-top
proc
opt
memory -nomap
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=4'b0000 %i
design -reset
# Good case 3: write ports with soft priority logic already
read_verilog << EOT
module top(
input [3:0] wa1, wa2, ra, wd1, wd2,
input clk, we1, we2,
output [3:0] rd);
reg [3:0] mem[0:15];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1)
mem[wa1] <= wd1;
if (we2 && wa1 != wa2)
mem[wa2] <= wd2;
end
endmodule
EOT
hierarchy -auto-top
proc
opt
memory -nomap
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=4'b0000 %i
design -reset
# Good case 4: two wide write ports
read_verilog << EOT
module top(
input [5:0] wa1, wa2,
input [7:0] ra,
input [31:0] wd1, wd2,
input clk, we1, we2,
output [7:0] rd);
reg [7:0] mem[0:255];
assign rd = mem[ra];
always @(posedge clk) begin
if (we1) begin
mem[{wa1, 2'b00}] <= wd1[7:0];
mem[{wa1, 2'b01}] <= wd1[15:8];
mem[{wa1, 2'b10}] <= wd1[23:16];
mem[{wa1, 2'b11}] <= wd1[31:24];
end
if (we2) begin
mem[{wa2, 2'b00}] <= wd2[7:0];
mem[{wa2, 2'b01}] <= wd2[15:8];
mem[{wa2, 2'b10}] <= wd2[23:16];
mem[{wa2, 2'b11}] <= wd2[31:24];
end
end
endmodule
EOT
hierarchy -auto-top
proc
opt
opt_mem_priority
memory_collect
select -assert-count 1 t:$mem_v2
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=64'h0804020100000000 %i
memory_share
select -assert-count 1 t:$mem_v2 r:WR_PRIORITY_MASK=64'h0f0f0f0f00000000 %i
select -assert-count 1 t:$mem_v2 r:WR_WIDE_CONTINUATION=8'hee %i
|
