computechecksum.m

来自「基于串行接口的GPS驱动程序」· M 代码 · 共 13 行

function cksum = ComputeChecksum(id, data, type)

if (nargin < 3)
    type = 'uchar';
end

% Compute the 2s complement of the sum of the bytes sent:
%    DLE, ID, SIZE, DATA
s = id + (length(data)*sizeof(type)) + sum(data);
cmp = bitcmp(s, 32);
cmp = cmp + 1;
cksum = bitand(cmp, 255);