IIC_Read.zip_MSP430F5

#include <msp430f5438.h> unsigned char *PRxData; // Pointer to RX data unsigned int RXByteCtr; volatile unsigned char RxBuffer[]; // Allocate array of RAM void Init_IIC(void) { UCB3CTL1 |= UCSWRST; // Enable SW reset UCB3CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB3CTL1 = UCSSEL_2; // Use SMCLK UCB3BR0 = 10; // fSCL = SMCLK/10 = ~100kHz UCB3BR1 = 0; UCB3I2CSA = 0x50; // Slave Address is 50h UCB3CTL1 &= ~UCSWRST; // Clear SW reset, resume operation } void EEPROM_RandomRead(void) { while(UCB3STAT & UCBBUSY); // Busy Judge UCB3IE = UCTXIE; // Enable TX interrupt UCB3IFG &= ~UCTXIFG; // Clear interrupt flag UCB3CTL1 |= UCTXSTT + UCTR; // I2C start condition, R/W = 0 TX model UCB3TXBUF = 0x01; // High address while(!(UCB3IFG & UCTXIFG)); // interrupt flag Judge UCB3TXBUF = 0x00; // Low address while(!(UCB3IFG & UCTXIFG)); // interrupt flag Judge UCB3IFG &= ~UCTXIFG; // Clear interrupt flag while(UCB3CTL1 & UCTXSTP); // start condition Judge UCB3IE = UCRXIE; // Enable RX interrupt UCB3IFG &= ~UCRXIFG; // Clear interrupt flag UCB3CTL1 &= ~UCTR; // R/W = 1, RX model UCB3CTL1 |= UCTXSTT; // Set start } int main(void) { PRxData = (unsigned char *)RxBuffer; // Start of RX buffer RXByteCtr = 0x3FFF; // Load RX byte counter WDTCTL = WDTPW + WDTHOLD; // Stop WDT P10SEL |= 0x06; // Assign I2C pins to USCI_B3 P1DIR |= BIT0; Init_IIC(); // __delay_cycles(1000); EEPROM_RandomRead(); while (1) { __bis_SR_register(LPM0_bits + GIE); // Enter LPM0, enable interrupts // Remain in LPM0 until all data // is RX'd __no_operation(); // Set breakpoint >>here<< and } } #pragma vector = USCI_B3_VECTOR __interrupt void USCI_B3_ISR(void) { switch(__even_in_range(UCB3IV,12)) { case 0: break; // Vector 0: No interrupts case 2: break; // Vector 2: ALIFG case 4: break; // Vector 4: NACKIFG case 6: break; // Vector 6: STTIFG case 8: break; // Vector 8: STPIFG case 10: // Vector 10: RXIFG RXByteCtr--; // Decrement RX byte counter if (RXByteCtr) { *PRxData++ = UCB3RXBUF; // Move RX data to address PRxData if (RXByteCtr == 1) // Only one byte { UCB3CTL1 |= UCTXSTP; // Generate I2C stop condition UCB3IE |= UCNACKIE; // Clear interrupt flag } } else { *PRxData = UCB3RXBUF; // Move final RX data to PRxData __bic_SR_register_on_exit(LPM0_bits); // Exit active CPU } P1OUT ^= BIT0; break; case 12: break; // Vector 12: TXIFG default: break; } }