Interrupt Servicing - Analog Devices ADSP-BF506F Hardware Reference Manual

Programming Examples
W[P0 + (DMA4_X_MODIFY - DMA4_CONFIG)] = R1;
/* start_address register points to memory buffer to be
transmitted from */
R1.l = tx_buf;
R1.h = tx_buf;
[P0 + (DMA4_START_ADDR - DMA4_CONFIG)] = R1;
BITSET(R0,0);
W[P0] = R0;

Interrupt Servicing

The receive channel and the transmit channel will each generate an inter-
rupt request if so programmed. The following code fragments show the
minimum actions that must be taken. Not shown is the programming of
the core and system event controllers.
Listing 19-3. Servicing an Interrupt
RECEIVE_ISR:
[--SP] = RETI;
/* clear DMA interrupt request */
P0.h = hi(DMA3_IRQ_STATUS);
P0.l = lo(DMA3_IRQ_STATUS);
R1 = 1;
W[P0] = R1.l;
RETI = [SP++];
rti;
19-74
/* X_modify register */
/* R0 still contains value of CONFIG register -
set bit 0 */
/* enable DMA channel (SPORT not enabled yet) */
/* nesting of interrupts */
/* write one to clear */
ADSP-BF50x Blackfin Processor Hardware Reference