ST SPC560P34 - Page 435

RM0046 DMA Channel Mux (DMA_MUX)
Doc ID 16912 Rev 5 435/936
volatile unsigned char *CHCONFIG15= (volatile unsigned char *)
(DMAMUX_BASE_ADDR+0x000F);
In File main.c:
#include "registers.h"
:
:
*CHCONFIG2 = 0x00;
*CHCONFIG2 = 0x85;
Disabling a source:
A particular DMA source may be disabled by not writing the corresponding source value into
any of the CHCONFIG registers. Additionally, some module specific configuration may be
necessary. Please refer to the appropriate section for more details.
Switching the source of a DMA channel:
1. Disable the DMA channel in the DMA and reconfigure the channel for the new source.
2. Clear the ENBL and TRIG bits of the DMA channel.
3. 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 10Switch DMA Channel 8 from source #5 transmit to source #7 transmit
1. In the DMA configuration registers, disable DMA channel 8 and reconfigure it to handle
the DSPI_0 transmits. This example assumes channel 0..7 have triggering capability
(#TRG = 8).
2. Write 0x00 to CHCONFIG8 (Base Address + 0x08).
3. Write 0x87 to CHCONFIG8 (Base Address + 0x08). In this case, setting the TRIG bit
would have no effect, because channels 8 and above do not support the periodic
triggering functionality.
The following code example illustrates steps 2 and 3 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);