MSP430FR2433 low power UART from ACLK?

Hello All,

I am designing a program with low power consumption sensor.

I would like to set up the UART module to use ACLK in low power mode.

The program wakes up every 500ms and performs a measurement and should send 8 bytes of data at a baudrate under 9600 bps.

The lowest power consumption I obtained running the  MCU at 8MHz.

UART consumes an additional 4-5µA sending 8 bytes of data.

Below is the actual setting of the UART, sourced from SMCLK at 8MHz.

UCA1CTLW0 |= UCSWRST;
UCA1CTLW0 |= UCSSEL__SMCLK;

UCA1BR0 = 52;
UCA1BR1 = 0x00;
UCA1MCTLW = 0x4900 | UCOS16 | UCBRF_1;

EUSCI_A_UART_clearInterrupt(EUSCI_A1_BASE, EUSCI_A_UART_RECEIVE_INTERRUPT);

// Enable USCI_A0 RX interrupt
EUSCI_A_UART_enableInterrupt(EUSCI_A1_BASE, EUSCI_A_UART_RECEIVE_INTERRUPT); // Enable interrupt
EUSCI_A_UART_enableInterrupt(EUSCI_A1_BASE, EUSCI_A_UART_TRANSMIT_INTERRUPT); // Enable interrupt