SLAA380B December   2007  – September 2018 MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619

 

  1.   Migrating From MSP430F16x MCUs to MSP430F261x MCUs
    1.     Trademarks
    2. 1 Comparison of MSP430F1xx and MSP430F2xx Families
    3. 2 Hardware Considerations for MSP430F16x to MSP430F261x 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 MSP430F16x to MSP430F261x Migration – Firmware Considerations
      1. 3.1 CPU and Memory Considerations
        1. 3.1.1 Extended Memory Architecture
        2. 3.1.2 Subroutine Parameter Passing and Stack Frame
        3. 3.1.3 MSP430X Instruction Cycle Count Optimizations
        4. 3.1.4 Device Memory Map
        5. 3.1.5 Information Flash Memory
      2. 3.2 Serial Communication – USART Versus USCI
        1. 3.2.1 UART Mode
        2. 3.2.2 SPI Mode
        3. 3.2.3 I2C 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
      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 MSP430F261x USCI in UART mode and that of the MSP430F16x USART is almost identical. The major differences are:

  • The MSP430F261x 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 must 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 MSP430F16x USART would be able to provide.
  • The start edge detection and clock activation schemes differ between the two devices. The MSP430F261x features a simplified scheme, in which 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 MSP430F16x UART, an interrupt is generated at start edge detection; therefore, the application must handle the clock source activation itself and then, as a second step, the character reception.
  • On the MSP430F261x USCI, interrupt flags are no longer cleared automatically upon entering the interrupt service routine.