
RM0453 Rev 2
487/1454
RM0453
DMA request multiplexer (DMAMUX)
497
Figure 51. Synchronization mode of the DMAMUX request line multiplexer channel
Figure 52. Event generation of the DMA request line multiplexer channel
If EGE is enabled, the multiplexer channel generates a channel event, as a pulse of one
AHB clock cycle, when its DMA request counter is automatically reloaded with the value of
the programmed NBREQ field, as shown in
and
MSv41974V1
Selected DMA request line transferred to the output
DMA request counter
dmamux_evtx
dmamux_req_outx
dmamux_syncx
Selected
dmamux_reqx
Synchronization event
Input DMA request line connected to output
3
2
1
0
4
4
DMA request counter underrun
DMA request counter auto-reload to NBREQ
Input DMA request line disconnected from output
Example: DMAMUX_CCRx configured with: NBREQ=4, SE=1, EGE=1, SPOL=01 (rising edge)
Not pending
DMA request pending
DMA requests served
MSv41975V1
DMA request counter
dmamux_evtx
2
3
DMA request counter reaches zero
Event is generated on the output
DMA request counter auto-reloads with NBREQ value
Example with: DMAMUX_CCRx configured with: NBREQ=3, SE=0, EGE=1
1
0
3
2
1
0
3
2
1
0
SE
EGE
Selected DMA request line transferred to the output
Selected
dmamux_reqx
dmamux_req_outx
Not pending
DMA request pending