Intel 386

12-53
DMA CONTROLLER
/* given channel*/
}
/*****************************************************************************
DisableDMAHWRequests:
Description:
Disables channel hardware requests for the given DMA channel.
The channel, however, can still receive software requests.
Parameters:
nChannel --channel to mask hardware requests
Returns:
Error Code
Assumptions:
None
Syntax:
int error_code;
error_code = DisableDMAHWRequests(DMA_Channel0);
Real/Protected Mode:
No changes required
*****************************************************************************/
int DisableDMAHWRequests(int nChannel)
{
WORD regDMAMSK = 0;
//Check input
if ( (nChannel != DMA_Channel0) && (nChannel != DMA_Channel1) )
return ERR_BADINPUT;
regDMAMSK = nChannel; //Set regDMAMSK[CS] to channel
regDMAMSK &= 0x04; //Set regDMAMSK[HRM]
_SetEXRegByte(DMAMSK, regDMAMSK); //Set hw request mask for given
//channel
return ERR_NONE;
}
/*****************************************************************************
SetDMAReqIOAddr: