AD4134 24bit数据模式 CRC校验
校验代码如下：
// CRC polynomial: x^6 + x^5 + x^2 + x + 1 (binary: 1100111)
// Function to calculate CRC
function [0:0] calculate_crc;
input [31:0] data; // 32-bit input data
localparam POLY = 7'b1100111; // Polynomial
localparam SEED_VALUE = 6'b100101; // Fixed seed value
// Intermediate variables
reg [32:0] temp_data; // 33-bit temporary data for CRC calculation
reg [6:0] remainder; // 7-bit remainder
integer i;
// Step 1: XOR the high 6 bits with SEED_VALUE
temp_data[32:26] = data[31:26] ^ 6'b100101; // XOR operation
temp_data[25:0] = data[25:0]; // Lower 26 bits remain unchanged
// Step 2: Initialize remainder
remainder = 7'b0;
// Step 3: Perform polynomial division
for (i = 32; i >= 0; i = i - 1) begin
// Shift the remainder and bring in the next bit
remainder = {remainder[5:0], temp_data[i]}; // Shift left, bring in next bit
// If the leading bit is 1, perform polynomial division
if (remainder[6]) begin
remainder = remainder ^ POLY; // XOR with POLY
end
end
// Step 4: Check if remainder is zero
if (remainder == 7'b0000000) begin
calculate_crc = 0; // Valid
end else begin
calculate_crc = 1; // Invalid
end
endfunction
