ST SPC560P34 - Page 433

RM0046 DMA Channel Mux (DMA_MUX)
Doc ID 16912 Rev 5 433/936
1. Determine with which DMA channel the source will be associated. Remember that only
the first four DMA channels have periodic triggering capability.
2. Clear the ENBL and TRIG bits of the DMA channel.
3. Ensure that the DMA channel is properly configured in the DMA. The DMA channel
may be enabled at this point.
4. In the PIT, configure the corresponding timer.
5. Select the source to be routed to the DMA channel. Write to the corresponding
CHCONFIG register, ensuring that the ENBL and TRIG bits are set.
Example 8Configure source #5 Transmit for use with DMA channel 2, with periodic
triggering capability
1. Write 0x00 to CHCONFIG2 (Base Address + 0x02).
2. Configure Channel 2 in the DMA, including enabling the channel.
3. Configure Timer 3 in the Periodic Interrupt Timer (PIT) for the desired trigger interval.
4. Write 0xC5 to CHCONFIG2 (Base Address + 0x02).
The following code example illustrates steps 1 and 4 above:
In File registers.h:
#define DMAMUX_BASE_ADDR 0xFC084000/* Example only ! */
/* Following example assumes char is 8-bits */
volatile unsigned char *CHCONFIG0 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0000);
volatile unsigned char *CHCONFIG1 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0001);
volatile unsigned char *CHCONFIG2 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0002);
volatile unsigned char *CHCONFIG3 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0003);
volatile unsigned char *CHCONFIG4 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0004);
volatile unsigned char *CHCONFIG5 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0005);
volatile unsigned char *CHCONFIG6 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0006);
volatile unsigned char *CHCONFIG7 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0007);
volatile unsigned char *CHCONFIG8 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0008);
volatile unsigned char *CHCONFIG9 = (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x0009);
volatile unsigned char *CHCONFIG10= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000A);
volatile unsigned char *CHCONFIG11= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000B);
volatile unsigned char *CHCONFIG12= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000C);
volatile unsigned char *CHCONFIG13= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000D);
volatile unsigned char *CHCONFIG14= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000E);
volatile unsigned char *CHCONFIG15= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000F);
In File main.c: