msp430x54x_mpy_12.c

来自「MSP430的开发程序的例子+中文注释」· C语言 代码 · 共 47 行

//******************************************************************************
//  msp430FG5438 Demo - 32x32 Unsigned Multiply Accumalate
//
//  Description: Hardware multiplier is used to multiply-accumalate a set of 
//  numbers. The first calculation is automatically initiated after the second 
//  operand is loaded. A second multiply-accumulate operation is performed next.
//  Results are stored in RES0, RES1, RES2 and RES3.  
//  SUMEXT contains the extended sign of the result.
//
//   ACLK = 32.768kHz, MCLK = SMCLK = default DCO
//
//                msp430FG5438
//             -----------------
//         /|\|                 |
//          | |                 |
//          --|RST              |
//            |                 |
//            |                 |
//
//   M Smertneck
//   Texas Instruments Inc.
//   April 2008
//   Built with CCEv3.2 IAR Embedded Workbench Version: 3.42A
//******************************************************************************

#include <msp430x54x.h>

void main(void)
{
  WDTCTL = WDTPW+WDTHOLD;                   // Stop WDT

                                            // unsigned multiply
  MPY32L = 0x1234;                          // Load lower 16 bits of operand 1
  MPY32H = 0x1234;                          // Load upper 16 bits of operand 1
  
  OP2L = 0x5678;                            // Load lower 16 bits of operand 2
  OP2H = 0x5678;                            // Load upper 16 bits of operand 2
                                            // unsigned MAC
  MAC32L = 0x1234;                          // Load lower 16 bits of operand 1
  MAC32H = 0x1234;                          // Load upper 16 bits of operand 1
  
  OP2L = 0x5678;                            // Load lower 16 bits of operand 2
  OP2H = 0x5678;                            // Load upper 16 bits of operand 2 
  
  _BIS_SR(LPM4_bits);                       // LPM4
}