【原创】基于FPGA的等精度测频方法（学习实验）

【原创】基于FPGA的等精度测频方法（学习实验）

1、多周期等精度测频的时序
module mesureFreq (
input fx,
input fbase,
input fgate,
output reg[31:0] fxCnt,
output reg[31:0] fbaseCnt
);

reg startCnt;
reg[31:0] fxCntTemp,fbaseCntTemp;

always @ (posedge fbase) begin
if(startCnt)
fbaseCntTemp <= fbaseCntTemp + 1;
else
fbaseCntTemp <= 32'h00000000;
end

always @ (posedge fx) begin
if(startCnt)
fxCntTemp <= fxCntTemp + 1;
else
fxCntTemp <= 32'h00000000;
end

//synchronous fgate
always @ (posedge fx) begin
if(fgate)
startCnt <= 1'b1;
else
startCnt <= 1'b0;
end

//output
always @ (negedge startCnt) begin
fxCnt <= fxCntTemp;
fbaseCnt <= fbaseCntTemp;
end

endmodule
4、综合后逻辑电路