SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The DMA uses incrementing bursts for transferring data. The burst transfer begins when the USB DMA is given bus mastership and when the address accesses a new 1-Kb block.
Bursts may be done in increments of 4, 8, 16, or of an unspecified length, depending on how the BRSTM field is configured in the USBDMACTLn register, the size of the packet being transferred and the location relative to the next 1-Kb boundary. For example if BRSTM = 0x2, increments of 8 or 4 bursts and bursts of unspecified length are allowed but not 16-byte bursts. There is no restriction on the BRSTM value for transfers in either DMA Mode 0 or DMA Mode 1.
Each transfer of a packet is generally a word transfer, but there may be additional byte or half-word transfers