MSP430 Problems with compatibility

Question

I'm using an MSP430 Launchpad. To be more specific I'm using the microcontroler MS430G2553. I was trying to compile some code designed for the MS430G2230 but the problem is that some parts of the code wont match the MS430G2553. This is the code

void USI_Init (void)
{
 // configure SPI
 USICTL0 |= USISWRST;                      // USI in reset
 USICTL0 = USICTL0 | USILSB;               // Least Significant Bit first
 USICTL0 |= USIPE7 + USIPE6 + USIPE5 + USIMST + USIOE; // Port, SPI Master
 USICTL1 |= USICKPH;                       // flag remains set
 USICKCTL = USIDIV_1 + USISSEL_2;          // /2 SMCLK
 USICTL0 &= ~USISWRST;                     // USI released for operation
 USICNT = USICNT | 0x50;                   // 16 bit mode; 16 bit to be    transmitted/received
 return;
}

and this is the second routine that doesn't work

#pragma vector=WDT_VECTOR
__interrupt void Write_Matrix(void)
{
static unsigned char index=0;

 P1OUT |= DATA_LATCH_PIN;
 P1OUT &= ~DATA_LATCH_PIN;

  USICTL1 &= ~USIIFG;           // Clears the interrupt flag
  USISRH = 1<<index;            // Move the index of the column in the high bits of USISR
  USISRL = Matrix[index];       // Move the index of the rows (value of Matrix[index]) in the low bits of USIRS
  USICNT = USICNT | 0x10;       // 16 bit format
 index = (index+1) & 7;

 return;
}

Any Ideas? Thanks

Answer 1

First off, you shouldn't expect to have code that is 100% portable between those two families of processors. The MSP430G2553 is a much larger value line processor and comes with more peripherals than the MSP430G2230.

Please refer to the following diagrams:

MSP430G2230 Functional Diagram

MSP430G2553 Functional Diagram

As you can see, these MCUs are very different.

Your first routine doesn't work because the MSP430G2553 doesn't have a USI peripheral. Instead, SPI communication is performed using a USCI peripheral. You will need to modify your code to use this peripheral instead. Please reference the User's Guide for more information.

Your second routine doesn't work because of the lack of USI peripheral again. Notice the references to USI registers: USICTL1 &= ~USIIFG;, etc. You will need to once again modify your code to use the USCI peripheral.