关于casex内部有无顺序,有顺序,顺序选择第一个写的的:
测试源码:
`timescale 10ns/10ns
module casex0;
reg A = 1'b0;
reg B = 1'b0;
integer i = 1'b0;
reg [4:0]ADDR = 5'b0x000;
always
begin
for(i = 0;i < 3;i = i+1)
begin
casex(ADDR)
5'b00??? : A = 1'b1;
5'b01??? : B = 1'b1;
5'b10?00 , 5'b11?00 :
begin
A = 1'b1;
B = 1'b1;
end
endcase
$display("ADDR = %b A = %b B = %b /n/n",ADDR,A,B);
A = 1'b0;
B = 1'b0;
if(i == 0) ADDR = 5'b01xxx;
else
if(i == 1)ADDR = 5'b10xxx;
else ADDR = 5'b11xxx;
end
end
endmodule`tim