|
楼主 |
发表于 2009-12-5 14:00:29
|
显示全部楼层
我写了很简单的代码来测试,结果还是不对,只有0.333V。
测试代码如下(verilog):
module testsstl( input clk, input din, output [1:0] dout );
reg [7:0] count;
always@(posedge clk)
count <= count + 1;
assign dout[0] = count[7];
assign dout[1] = din;
endmodule
约束文件如下(ucf):其中din和dout分配到BANK3,采用SSTL18_II
NET "clk" LOC = A9;
NET "din" LOC = U1;
NET "dout[0]" LOC = J6;
NET "dout[1]" LOC = H4;
#CONFIG VREF = G1, M2, T1, J7, G6, P7;
NET "clk" IOSTANDARD = LVCMOS33;
NET "clk" DRIVE = 8;
NET "din" IOSTANDARD = SSTL18_II;
NET "dout[0]" IOSTANDARD = SSTL18_II;
NET "dout[1]" IOSTANDARD = SSTL18_II; |
|