Analog Devices ADuCM355 Hardware Reference Manual page 169

ADuCM355 Hardware Reference Manual
Peripheral Ping Pong DMA Transfer (CHNL_CFG, Bits[2:0] = 011)
In this mode, if the DMA request is from a peripheral, the peripheral must send DMA requests after every data transfer to complete primary or
alternate descriptor tasks and the final descriptor must be programmed to use a basic transfer type. This mode is shown in Figure 45.
TASK A: PRIMARY, CYCLE_CTRL = 011, 2
TASK A
SOFTWARE REQUEST
TASK B: ALTERNATE, CYCLE_CTRL = 011, 2
SOFTWARE REQUEST
AUTOMATIC REQUESTS
TASK C: PRIMARY, CYCLE_CTRL = 011, 2
TASK C
SOFTWARE REQUEST
TASK D: ALTERNATE, CYCLE_CTRL = 011, 2
SOFTWARE REQUEST
AUTOMATIC REQUESTS
TASK E: PRIMARY, CYCLE_CTRL = 011, 2
TASK E
SOFTWARE REQUEST
AUTOMATIC REQUESTS
END: ALTERNATE, CYCLE_CTRL = 000
Figure 44. Software Ping Pong DMA Transfer
TASK A: PRIMARY, CYCLE_CTRL = 011, 2
TASK A
REQUESTS
TASK B: ALTERNATE, CYCLE_CTRL = 011, 2
REQUESTS
TASK C: PRIMARY, CYCLE_CTRL = 011, 2
TASK C
REQUESTS
TASK D: ALTERNATE, CYCLE_CTRL = 011, 2
REQUESTS
TASK E: PRIMARY, CYCLE_CTRL = 011, 2
TASK E
REQUESTS
END: ALTERNATE, CYCLE_CTRL = 000
Figure 45. Peripheral Ping Pong DMA Transfer
Rev. B | Page 169 of 312
R
= 4, N = 6
DMA_DONE[C]
R
= 4, N = 12
TASK B
DMA_DONE[C]
R
= 2, N = 2
DMA_DONE[C]
R
= 4, N = 5
TASK D
DMA_DONE[C]
R
= 4, N = 7
DMA_DONE[C]
AUTO REQUEST
R
= 4, N = 6
DMA_DONE[C]
R
= 4, N = 12
TASK B
DMA_DONE[C]
R
= 2, N = 2
DMA_DONE[C]
R
= 4, N = 5
TASK D
DMA_DONE[C]
R
= 4, N = 7
DMA_DONE[C]
INVALID
UG-1262