eUSCI_A Operation – UART Mode
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SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Enhanced Universal Serial Communication Interface (eUSCI) – UART Mode
Example 30-1. UCAxIV Software Example
#pragma vector = USCI_A0_VECTOR __interrupt void USCI_A0_ISR(void) {
switch(__even_in_range(UCA0IV,18)) {
case 0x00:
// Vector 0: No interrupts
break;
case 0x02: ...
// Vector 2: UCRXIFG
break;
case 0x04: ...
// Vector 4: UCTXIFG
break;
case 0x06: ...
// Vector 6: UCSTTIFG
break;
case 0x08: ...
// Vector 8: UCTXCPTIFG
break;
default: break;
}
}
30.3.16 DMA Operation
In devices with a DMA controller, the eUSCI module can trigger DMA transfers when the transmit buffer
UCAxTXBUF is empty or when data was received in the UCAxRXBUF buffer. The DMA trigger signals
correspond to the UCTXIFG transmit interrupt flag and the UCRXIFG receive interrupt flag, respectively.
The interrupt functionality must be disabled for the selected DMA triggers with UCTXIE = 0 and UCRXIE =
0.
A DMA read access to UCAxRXBUF has the same effects as a CPU (software) read: all error flags
(UCRXERR, UCFE, UCPE, UCOE, and UCBRK) are cleared after the read. Thus these errors might go
unnoticed.