void IspSpiDMA_Rx(uint8_t *pbuf,uint16_t length)
{
bool intDisabled;
unsigned char txTrash[3000];
// pbuf points to uint8_t array of data to be received from MRF
// length indicates number of bytes to read
intDisabled = WF_EintIsDisabled();
WF_EintDisable();
IEC1CLR=0x00030000; // disable DMA channel 0&1 interrupts
IFS1CLR=0x00030000; // clear existing DMA channel 0&1 interrupt flag
PLIB_DMA_Enable(0); // DMACONSET=0x00008000; // enable the DMA controller
PLIB_DMA_ChannelXPrioritySelect(0,DMA_CHANNEL_0, DMA_CHANNEL_PRIORITY_3);//DCH0CONSET = 0x3; // channel off, pri 3, no chaining
PLIB_DMA_ChannelXChainDisable(0,DMA_CHANNEL_0);
PLIB_DMA_ChannelXPrioritySelect(0,DMA_CHANNEL_1, DMA_CHANNEL_PRIORITY_2);// DCH1CONSET = 0x03;//0x62;
PLIB_DMA_ChannelXChainEnable(0,DMA_CHANNEL_1);
DCH0ECONCLR=0xFFFFFFFF; // no start or stop irq?s, no pattern match
DCH1ECONCLR=0xFFFFFFFF; // no start or stop irq?s, no pattern match
// program the transfer
PLIB_DMA_ChannelXSourceStartAddressSet (0,DMA_CHANNEL_0, ((unsigned long int)txTrash) & 0x1FFFFFFFL);
PLIB_DMA_ChannelXDestinationStartAddressSet(0,DMA_CHANNEL_1, ((unsigned long int)pbuf) & 0x1FFFFFFFL);
if( MRF24W_SPI_CHN == 1)
{
PLIB_DMA_ChannelXDestinationStartAddressSet(0,DMA_CHANNEL_0, ((unsigned long int)&SPI1BUF) & 0x1FFFFFFFL);
PLIB_DMA_ChannelXSourceStartAddressSet (0,DMA_CHANNEL_1, ((unsigned long int)&SPI1BUF) & 0x1FFFFFFFL);
}
else if( MRF24W_SPI_CHN == 2)
{
PLIB_DMA_ChannelXDestinationStartAddressSet(0,DMA_CHANNEL_0, ((unsigned long int)&SPI2BUF) & 0x1FFFFFFFL);
PLIB_DMA_ChannelXSourceStartAddressSet (0,DMA_CHANNEL_1, ((unsigned long int)&SPI2BUF) & 0x1FFFFFFFL);
}
PLIB_DMA_ChannelXSourceSizeSet (0,DMA_CHANNEL_0,length);
PLIB_DMA_ChannelXDestinationSizeSet(0,DMA_CHANNEL_0,1 );
PLIB_DMA_ChannelXCellSizeSet (0,DMA_CHANNEL_0,1 );
PLIB_DMA_ChannelXSourceSizeSet (0,DMA_CHANNEL_1,1);
PLIB_DMA_ChannelXDestinationSizeSet(0,DMA_CHANNEL_1,length);
PLIB_DMA_ChannelXCellSizeSet (0,DMA_CHANNEL_1,1 );
DCH0INTCLR=0x00ff00ff; // clear existing events, disable all interrupts
DCH1INTCLR=0x00ff00ff; // clear existing events, disable all interrupts
// initiate a transfer
PLIB_DMA_ChannelXStartIRQSet(0, DMA_CHANNEL_0, DMA_TRIGGER_SPI_1_TRANSMIT);
PLIB_DMA_ChannelXTriggerEnable(0, DMA_CHANNEL_0, DMA_CHANNEL_TRIGGER_TRANSFER_START);
PLIB_DMA_ChannelXStartIRQSet(0, DMA_CHANNEL_1, DMA_TRIGGER_SPI_1_RECEIVE);
PLIB_DMA_ChannelXTriggerEnable(0, DMA_CHANNEL_1, DMA_CHANNEL_TRIGGER_TRANSFER_START);
PLIB_DMA_ChannelXEnable(0,DMA_CHANNEL_0);
PLIB_DMA_ChannelXEnable(0,DMA_CHANNEL_1);
// DCH0ECONSET=0x00000080; // set CFORCE to 1
// do something else
// poll to see that the transfer was done
while(true)
{
register int pollCnt; // use a poll counter.
// continuously polling the DMA controller in a tight
// loop would affect the performance of the DMA transfer
int dma0Flags=DCH0INT;
int dma1Flags = DCH1INT;
if((dma0Flags&0xb)&&(dma1Flags&0xb))
{ // one of CHERIF (DCHxINT<0>), CHTAIF (DCHxINT<1>)
// or CHBCIF (DCHxINT<3>) flags set
break; // transfer completed
}
pollCnt=length<<1; // use an adjusted value here
while(pollCnt--); // wait before reading again the DMA controller
}
PLIB_DMA_Disable(0);
if(!intDisabled)
{
WF_EintEnable();
}
}
void SYS_DMA_ChannelSetup
(
SYS_DMA_CHANNEL_HANDLE handle,
SYS_DMA_CHANNEL_OP_MODE modeEnable,
DMA_TRIGGER_SOURCE eventSrc
)
{
SYS_DMA_CHANNEL_OBJECT *chanObj;
DMA_CHANNEL channelNumber;
chanObj = (SYS_DMA_CHANNEL_OBJECT *) handle;
channelNumber = (chanObj - (SYS_DMA_CHANNEL_OBJECT *) &gSysDMAChannelObj[0]);
/* Setup the channel modes */
/* Basic mode, nothing specifically needs to be set */
if(SYS_DMA_CHANNEL_OP_MODE_BASIC & modeEnable)
{
/* Do nothing */
;
}
/* Pattern match Abort */
if(SYS_DMA_CHANNEL_OP_MODE_MATCH_ABORT & modeEnable)
{
PLIB_DMA_ChannelXTriggerEnable( DMA_ID_0, channelNumber,
DMA_CHANNEL_TRIGGER_PATTERN_MATCH_ABORT);
}
/* Channel chaining mode */
if(SYS_DMA_CHANNEL_OP_MODE_CHAIN_HIGH & modeEnable)
{
PLIB_DMA_ChannelXChainEnable( DMA_ID_0, channelNumber);
PLIB_DMA_ChannelXChainToHigher(DMA_ID_0, channelNumber);
PLIB_DMA_ChannelXDisabledEnablesEvents(DMA_ID_0, channelNumber);
}
else if(SYS_DMA_CHANNEL_OP_MODE_CHAIN_LOW & modeEnable)
{
PLIB_DMA_ChannelXChainEnable( DMA_ID_0, channelNumber);
PLIB_DMA_ChannelXChainToLower(DMA_ID_0, channelNumber);
PLIB_DMA_ChannelXDisabledEnablesEvents(DMA_ID_0, channelNumber);
}
else
{
;
}
/* Auto Enable mode */
if(SYS_DMA_CHANNEL_OP_MODE_AUTO & modeEnable)
{
PLIB_DMA_ChannelXAutoEnable( DMA_ID_0, channelNumber);
}
/* CRC Enable */
if(SYS_DMA_CHANNEL_OP_MODE_CRC & modeEnable)
{
PLIB_DMA_CRCEnable( DMA_ID_0);
}
/* Setup the DMA Trigger Source and Enable it */
if(DMA_TRIGGER_SOURCE_NONE == eventSrc)
{
/* This is polling mode of Implementation */
PLIB_DMA_ChannelXINTSourceEnable(DMA_ID_0, channelNumber,
DMA_INT_BLOCK_TRANSFER_COMPLETE);
PLIB_DMA_ChannelXINTSourceEnable(DMA_ID_0, channelNumber,
DMA_INT_ADDRESS_ERROR);
}
else
{
PLIB_DMA_ChannelXStartIRQSet( DMA_ID_0, channelNumber, eventSrc);
PLIB_DMA_ChannelXTriggerEnable( DMA_ID_0, channelNumber, DMA_CHANNEL_TRIGGER_TRANSFER_START);
/* We need to notify the user on the completion of a transfer request.
* Setting the DMA block completion transfer interrupt. */
PLIB_DMA_ChannelXINTSourceEnable(DMA_ID_0, channelNumber,
DMA_INT_BLOCK_TRANSFER_COMPLETE);
PLIB_DMA_ChannelXINTSourceEnable(DMA_ID_0, channelNumber,
DMA_INT_ADDRESS_ERROR);
}
return;
}
