Search code examples
uartmsp430

MSP430G2553 UART Baudrate and Control Registers. Can I use word access?

Is it possible to program MSP430G2553 UART registers with word access or are the internal peripherals only byte wide and therefore only byte accessible?

(I know that MCTL is only byte wide on this device.)

Solution

  • The 2xx family User's Guide says in section 1.4.3:

    The address space from 010h to 0FFh is reserved for 8-bit peripheral modules. These modules should be accessed with byte instructions. Read access of byte modules using word instructions results in unpredictable data in the high byte. If word data is written to a byte module only the low byte is written into the peripheral register, ignoring the high byte.