SLAZ388AH October   2012  – August 2021 MSP430FR5735

 

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6.17 DMA9

DMA Module

Category

Functional

Function

DMA stops transferring bytes unexpectedly

Description

When the DMA is configured to transfer bytes from the eUSCI_A or eUSCI_B transmit or receive buffers, the transmit or receive triggers (TXIFG and RXIFG) may not be seen by the DMA module and the transfer of the bytes is missed. Once the first byte in a transfer sequence is missed, all the following bytes are missed as well. All eUSCI_A modes (UART, SPI, and IrDA) and all eUSCI_B modes (SPI and I2C) are affected.

Workaround

1) Use Interrupt Service Routines to transfer data to and from the eUSCI_A or eUSCI_B.
OR
2) When using DMA channel 0 for transferring data to and from the eUSCI_A or eUSCI_B, use DMA channel 2 (lower priority than DMA channel 0) to read the same register of the eUSCI_A or eUSCI_B  that DMA channel 0 is working with. Use the same USCI IFG (e.g. UCA0RXIFG) as trigger source for these both DMA channels.