SLAA381C December   2007  – September 2018 MSP430F233 , MSP430F235 , MSP430F2410 , MSP430F247 , MSP430F248 , MSP430F249

 

  1.   Migrating From MSP430F13x and MSP430F14x MCUs to MSP430F23x and MSP430F24x MCUs
    1.     Trademarks
    2. 1 Comparison of MSP430F1xx and MSP430F2xx Families
    3. 2 Hardware Considerations for F13x/F14x to F23x/F24x Migration
      1. 2.1 Device Package and Pinout
      2. 2.2 Current Consumption
      3. 2.3 Operating Frequency and Supply Voltage
      4. 2.4 Device Errata
    4. 3 Firmware Considerations for F13x/F14x to F23x/F24x Migration
      1. 3.1 Memory Considerations
        1. 3.1.1 Device Memory Map
        2. 3.1.2 Information Flash Memory
      2. 3.2 Serial Communication – USART and USCI
        1. 3.2.1 UART Mode
        2. 3.2.2 SPI Mode
      3. 3.3 Clock System
        1. 3.3.1 LFXT1 and XT2 Oscillators
        2. 3.3.2 Digitally Controlled Oscillator (DCO)
      4. 3.4 Bootloader (BSL)
      5. 3.5 Interrupt Vectors
      6. 3.6 Beware of Reserved Bits!
      7. 3.7 Timers
      8. 3.8 Analog Comparator
    5. 4 References
  2.   Revision History

3.2.1 UART Mode

The operation of the F23x/F24x USCI in UART mode and that of the F13x/F14x USART are almost identical. The major differences are:

  • The F23x/F24x USCI uses a different baud rate generator. It utilizes a new modulation scheme, provides a two-stage modulator, and can be used to implement an oversampling baud rate generation scheme. During application migration, the baud rate register settings need to be recalculated. However, it is safe to say that the USCI module can be used to generate the same target baud rate using the same clock source that the F13x/F14x USART would be able to provide.
  • The start edge detection and clock activation schemes are different on the two devices. The F23x/F24x features a simplified scheme whereby the USCI module automatically activates the USCI module clock source upon start edge detection and then provides an interrupt to wake up the CPU after the entire character has been received. On the F13x/F14x UART, an interrupt is generated directly upon start edge detection, the application needs to handle the clock source activation itself, and then, as a second step, the character reception.
  • On the F23x/F24x USCI, interrupt flags are no longer cleared automatically upon entering the interrupt service routine.