DMA Operation
13-125
USB Function Module
Figure 13–44. Isochronous TX DMA Start Routine
ISO TXDMA[0,1, 2]
start routine
EP number
−−>
TXDMA_CFG.
Assign ISO endpoint number
to DMA channel n.
Application-specific
action to initialize the
main system DMA
controller
LH DMA write access
must point to
TXDCHn.TXDATn in
response to DMA
channel n request.
End of ISO TXDMA
[0,1, 2]
start routine
Start DMA transfer:
TXDMAn._TSC = FTZ,
TXDMAn.TXn_EOT = 1,
TXDMAn.TXn_Start = 1
If no interrupt is signaled to
the LH (except SOF if
enabled), the Device DMA
sends a new request to the LH
DMA controller every frame.
EOT bit is don’t care for ISO
endpoints.
TXDMAn_EP