Lab08-2_Keyboard.rar_MSP430F6638按键_msp430f6638_msp430f6638 I2C_m

/* * dr_i2c.c * * Created on: 2013-6-6 * Author: DengPihui */ #include <msp430.h> #include <stdint.h> #include "dr_i2c.h" #include "fw_public.h" #define OVERFLOW_ADD(val, limit) \ { \ val++; \ if(val >= (limit)) \ val = 0; \ } #define I2C_NONE -1 #define SS_WAIT_FOR_SEND_REG 0 #define SS_WAIT_FOR_SEND_DATA 1 #define SS_WAIT_FOR_END 2 #define RS_WAIT_FOR_SEND_REG 3 #define RS_WAIT_FOR_SEND_READ_START 4 #define RS_WAIT_FOR_RECV 5 #define RS_WAIT_FOR_RECV2 6 int curI2CStatus = I2C_NONE; void initI2C() { UCB0CTL1 |= UCSWRST; //复位UCB0 UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; //7位地址，单主机，本机为主机，I2C，同步 UCB0CTL1 = UCSSEL__SMCLK + UCSWRST; //选择SMCLK作为时钟，保持复位 UCB0BR0 = (SMCLK_FREQ / I2C_FREQ) & 0xFF; UCB0BR1 = ((SMCLK_FREQ / I2C_FREQ) >> 8) & 0xFF; P2SEL |= BIT1 + BIT2; //选择P2.1、P2.2的外设功能 P2MAP1 = PM_UCB0SDA; //P2.1作为SDA P2MAP2 = PM_UCB0SCL; //P2.2作为SCL UCB0CTL1 &= ~UCSWRST; //清除复位 UCB0IE |= UCNACKIE; //启用NACK中断 } typedef struct { uint8_t slave; uint8_t reg; uint8_t value; } I2C_TXREQ; #define TXREQ_BUFFER_SIZE 20 I2C_TXREQ tx_requests[TXREQ_BUFFER_SIZE]; int curSendingNo = 0, curTxEmptyNo = 0; int I2C_Send() { uint16_t gie; _ECRIT(gie); if(curI2CStatus != I2C_NONE) { _LCRIT(gie); return 0; } if(curSendingNo != curTxEmptyNo) { curI2CStatus = SS_WAIT_FOR_SEND_REG; //进入待发状态 UCB0I2CSA = tx_requests[curSendingNo].slave; //设定从机地址 UCB0CTL1 |= UCTR; //设置发送模式 UCB0CTL1 |= UCTXSTT; //发送START UCB0IE |= UCTXIE; //启用发送中断 UCB0IE &= ~UCRXIE; //关闭接收中断 _LCRIT(gie); return 1; } _LCRIT(gie); return 0; } int I2C_RequestSend(uint8_t slave, uint8_t reg, uint8_t value) { uint16_t gie; _ECRIT(gie); int temp = curTxEmptyNo; OVERFLOW_ADD(temp, TXREQ_BUFFER_SIZE); if(temp == curSendingNo) { _LCRIT(gie); return 0; //缓冲区接近溢出，不可写 } tx_requests[curTxEmptyNo].slave = slave; tx_requests[curTxEmptyNo].reg = reg; tx_requests[curTxEmptyNo].value = value; curTxEmptyNo = temp; I2C_Send(); _LCRIT(gie); return 1; } typedef struct { uint8_t slave; uint8_t reg; uint16_t value; uint8_t hasnew; } I2C_RXREG; #define RXREG_BUFFER_SIZE 20 I2C_RXREG rx_regs[RXREG_BUFFER_SIZE]; int rxreg_count = 0; int curRecvingNo = 0; int I2C_StartQuery() { if(curI2CStatus != I2C_NONE) return 0; if(rxreg_count == 0) return 0; int count = 0; while(rx_regs[curRecvingNo].hasnew != 0) { //当前考虑读取的位置的数据还未取出 OVERFLOW_ADD(curRecvingNo, rxreg_count); //测试下一个点 count++; if(count >= rxreg_count) //已全部检查一遍，无需要更新的点 return 0; } curI2CStatus = RS_WAIT_FOR_SEND_REG; UCB0I2CSA = rx_regs[curRecvingNo].slave; //设定从机地址 UCB0CTL1 |= UCTR; //设置发送模式 UCB0CTL1 |= UCTXSTT; //发送START UCB0IE |= UCTXIE; //启用发送中断 UCB0IE &= ~UCRXIE; //关闭接收中断 return 1; } int I2C_AddRegQuery(uint8_t slave, uint8_t reg) { uint16_t gie; _ECRIT(gie); if(rxreg_count >= RXREG_BUFFER_SIZE) { _LCRIT(gie); return -1; //满 } rx_regs[rxreg_count].slave = slave; rx_regs[rxreg_count].reg = reg; rx_regs[rxreg_count].value = 0; rx_regs[rxreg_count].hasnew = 0; rxreg_count++; I2C_StartQuery(); _LCRIT(gie); return rxreg_count-1; } int I2C_QueryHasNew(int index) { return rx_regs[index].hasnew; } uint16_t I2C_CheckQuery(int index) { rx_regs[index].hasnew = 0; uint16_t gie; _ECRIT(gie); I2C_StartQuery(); //现在可以开始新查询 _LCRIT(gie); return rx_regs[index].value; } #pragma vector=USCI_B0_VECTOR __interrupt void i2cInterrupt() { if(UCB0IFG & UCNACKIFG) { switch(curI2CStatus) { case SS_WAIT_FOR_SEND_REG: case SS_WAIT_FOR_SEND_DATA: case SS_WAIT_FOR_END: OVERFLOW_ADD(curSendingNo, TXREQ_BUFFER_SIZE); break; case RS_WAIT_FOR_SEND_REG: case RS_WAIT_FOR_SEND_READ_START: case RS_WAIT_FOR_RECV: case RS_WAIT_FOR_RECV2: OVERFLOW_ADD(curRecvingNo, rxreg_count); break; default: break; } curI2CStatus = I2C_NONE; //检查发送与接收均需要此状态 UCB0IFG = 0; if(!I2C_Send()) if(!I2C_StartQuery()) UCB0CTL1 |= UCTXSTP; } else { switch(curI2CStatus) { case SS_WAIT_FOR_SEND_REG: UCB0TXBUF = tx_requests[curSendingNo].reg; curI2CStatus = SS_WAIT_FOR_SEND_DATA; break; case SS_WAIT_FOR_SEND_DATA: UCB0TXBUF = tx_requests[curSendingNo].value; curI2CStatus = SS_WAIT_FOR_END; break; case SS_WAIT_FOR_END: curI2CStatus = I2C_NONE; //检查发送与接收均需要此状态 UCB0IE &= ~UCTXIE; OVERFLOW_ADD(curSendingNo, TXREQ_BUFFER_SIZE); UCB0CTL1 |= UCTXSTP; while(UCB0CTL1 & UCTXSTP); //等待发送STOP结束 __delay_cycles(100); //延迟5us if(!I2C_Send()) I2C_StartQuery(); /*if(!I2C_Send()) if(!I2C_StartQuery()) UCB0CTL1 |= UCTXSTP;*/ break; case RS_WAIT_FOR_SEND_REG: UCB0TXBUF = rx_regs[curRecvingNo].reg; curI2CStatus = RS_WAIT_FOR_SEND_READ_START; break; case RS_WAIT_FOR_SEND_READ_START: UCB0I2CSA = rx_regs[curRecvingNo].slave; //设定从机地址 UCB0CTL1 &= ~UCTR; //设置接收模式 UCB0CTL1 |= UCTXSTT; //发送START UCB0IE &= ~UCTXIE; //关闭发送中断 UCB0IE |= UCRXIE; //启动接收中断 curI2CStatus = RS_WAIT_FOR_RECV; break; case RS_WAIT_FOR_RECV: curI2CStatus = RS_WAIT_FOR_RECV2; rx_regs[curRecvingNo].value = UCB0RXBUF; //(UCB0RXBUF << 8) & 0xFF00; UCB0CTL1 |= UCTXSTP; //告知将在下一字节后停止 break; case RS_WAIT_FOR_RECV2: curI2CStatus = I2C_NONE; //检查发送与接收均需要此状态 UCB0IE &= ~UCRXIE; rx_regs[curRecvingNo].value |= (UCB0RXBUF << 8) & 0xFF00;//UCB0RXBUF; rx_regs[curRecvingNo].hasnew = 1; OVERFLOW_ADD(curRecvingNo, rxreg_count); //继续查询需要下一地址 while(UCB0CTL1 & UCTXSTP); //等待发送STOP结束 __delay_cycles(100); //延迟5us if(!I2C_Send()) I2C_StartQuery(); break; default: break; } } }