I2C主机模式接收的中断标志

457887107

I2C主机模式接收的中断标志 [复制链接]

1. //******************************************************************************

2. // MSP430G2xx3 Demo - USCI_B0 I2C Master RX single bytes from MSP430 Slave
3. //
4. // Description: This demo connects two MSP430's via the I2C bus. The master
5. // reads from the slave. This is the master code. The data from the slave
6. // transmitter begins at 0 and increments with each transfer. The received
7. // data is in R5 and is checked for validity. If the received data is
8. // incorrect, the CPU is trapped and the P1.0 LED will stay on. The USCI_B0
9. // RX interrupt is used to know when new data has been received.
10. // ACLK = n/a, MCLK = SMCLK = BRCLK = default DCO = ~1.2MHz
11. //
12. // /|\ /|\
13. // MSP430G2xx3 10k 10k MSP430G2xx3
14. // slave | | master
15. // ----------------- | | -----------------
16. // -|XIN P1.7/UCB0SDA|<-|---+->|P1.7/UCB0SDA XIN|-
17. // | | | | | 32kHz
18. // -|XOUT | | | XOUT|-
19. // | P1.6/UCB0SCL|<-+----->|P1.6/UCB0SCL |
20. // | | | P1.0|--> LED
21. //
22. // D. Dang
23. // Texas Instruments Inc.
24. // February 2011
25. // Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
26. //******************************************************************************
27. #include "msp430g2553.h"

    unsigned char RXData;

28. unsigned char RXCompare;

    void main(void)

29. {
30. WDTCTL = WDTPW + WDTHOLD; // Stop WDT
31. P1OUT &= ~BIT0; // P1.0 = 0
32. P1DIR |= BIT0; // P1.0 output
33. P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
34. P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
35. UCB0CTL1 |= UCSWRST; // Enable SW reset
36. UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode
37. UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset
38. UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz
39. UCB0BR1 = 0;
40. UCB0I2CSA = 0x048; // Slave Address is 048h
41. UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
42. IE2 |= UCB0RXIE; // Enable RX interrupt
43. RXCompare = 0; // Used to check incoming data

    while (1)

44. {
45. while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
46. UCB0CTL1 |= UCTXSTT; // I2C start condition
47. while (UCB0CTL1 & UCTXSTT); // Start condition sent?
48. UCB0CTL1 |= UCTXSTP; // I2C stop condition
49. __bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts

    if (RXData != RXCompare) // Trap CPU if wrong

50. {
51. P1OUT |= BIT0; // P1.0 = 1
52. while (1); // Trap CPU
53. }

    RXCompare++; // Increment correct RX value

54. }
55. }

    // USCI_B0 Data ISR

56. #pragma vector = USCIAB0TX_VECTOR
57. __interrupt void USCIAB0TX_ISR(void)
58. {
59. RXData = UCB0RXBUF; // Get RX data
60. __bic_SR_register_on_exit(CPUOFF); // Exit LPM0
61. }

复制代码

这个是官方例程, 主机模式接收从机发来的一个字节 我很困惑为什么接收模式 #pragma vector = USCIAB0TX_VECTOR 中断标志却是 TX呢 从机发送也是这个标志..... 有没有人可以讲解一下 多谢啦

457887107

中断程序 在最后几行

457887107

//------------------------------------------------------------------------------
// The USCIAB0TX_ISR is structured such that it can be used to transmit any
// number of bytes by pre-loading TXByteCtr with the byte count.
//------------------------------------------------------------------------------
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
  if (TXByteCtr)                            // Check TX byte counter
  {
    UCB0TXBUF = TXData;                     // Load TX buffer
    TXByteCtr--;                            // Decrement TX byte counter
  }
  else
  {
    UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
    IFG2 &= ~UCB0TXIFG;                     // Clear USCI_B0 TX int flag
    __bic_SR_register_on_exit(CPUOFF);      // Exit LPM0
  }
}


这是从机发送的
中断向量 也是 USCIAB0TX_VECTOR

457887107

xinlangtuibian

我也是相当郁闷 啊.....

457887107

好像 STT STP 的中断标志 进RX中断向量

TX RX中断标志   进TX中断向量

xinlangtuibian

怎么是这样子的勒...感觉有点乱了......你 是哪里找的资料啊....我现在想模拟的IIC了...

457887107

userguide 一个不起眼的小角落...

zwuguli

USCI_Ax和USCI_Bx共享相同的中断向量。I2C模块中状态变化中断标志位－USCI_Bx中的UCALIFG、UCNACKIFG、UCSTTIFG 、UCSTPIFG和USCI_Ax中的UCAxRXIFG使用同一个中断向量。I2C模块发送和接收中断标志－USCI_Bx中的UCBxTXIFG、UCBxRXIFG和USCI_Ax中的UCAxTXIFG共享另外一个中断向量。

[ 本帖最后由 zwuguli 于 2012-11-13 15:45 编辑 ]