请问在这个滤波函数中RESHI,RESLO, MACS,OP2等在哪定义的？

问题如题。

void ECG_FilterProcess(short * WorkingBuff, short * CoeffBuf, short* FilterOut)
{
short i, Val_Hi, Val_Lo;

RESHI = 0;
RESLO = 0;
MPYS = *WorkingBuff--; // Load first operand -unsigned mult
OP2 = *CoeffBuf++; // Load second operand

for ( i = 0; i < FILTERORDER/10; i++)
{
MACS = *WorkingBuff--; // Load first operand -unsigned mult
OP2 = *CoeffBuf++; // Load second operand

MACS = *WorkingBuff--; // Load first operand -unsigned mult
OP2 = *CoeffBuf++; // Load second operand

MACS = *WorkingBuff--; // Load first operand -unsigned mult
OP2 = *CoeffBuf++; // Load second operand

MACS = *WorkingBuff--; // Load first operand -unsigned mult
OP2 = *CoeffBuf++; // Load second operand