Intel 386 User Manual page 393

Intel386™ EX EMBEDDED MICROPROCESSOR USER'S MANUAL
Syntax:
InitDMA();
Real/Protected Mode:
No changes required
*****************************************************************************/
void InitDMA(void)
{
_SetEXRegByte(DMACLR, 0x0);
_SetEXRegByte(DMACMD1, 0x0);
_SetEXRegByte(DMACMD2, 0x8);
}
/*****************************************************************************
InitDMA1ForSSIXmitterToMem:
Description:
This function prepares DMA channel 1 for transfers between the async.
serial port transmitter (channel 0) and memory.
function, a DMA transfer can be initiated by setting the Target address,
setting the transfer count, and clearing the hardware request mask
for this DMA channel.
Parameters:
None
Returns:
None
Assumptions:
InitDMA() has been called to enable the peripheral.
Syntax:
static char lpsz[]="Hello World";
InitDMA();
InitDMA1ForSerialXmitter();
.
.
12-58
//Initialize DMA peripheral
/*Resets DMA peripheral*/
/*DMACMD1[7:5]=0: reserved*/
/*DMACMD1[4]=0: disable priority rotation*/
/* enable*/
/*DMACMD1[2]=0: enable channel's 0 and 1*/
/*DMACMD1[1:0]=0: reserved*/
/*DMACMD2[7:4]=0: reserved*/
/*DMACMD2[3:2]=2: assign HOLD to the lowest*/
/* priority level*/
/*DMACMD2[1]=0:
/*DMACMD2[0]=0:
//Initialize DMA peripheral
//Initialize DMA channel 1
EOP# samples input async.*/
DRQn samples input async.*/
After calling this