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发表于 2014-11-16 16:43:07
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void Timer3_ISR (void) interrupt 14
{
SMB0CF &= ~0x80; // Disable SMBus
SMB0CF |= 0x80; // Re-enable SMBus
TMR3CN &= ~0x80; // Clear Timer3 interrupt-pending flag
}
void PORT_Init (void)
{
P0MDOUT = 0x00; // All P0 pins open-drain output
XBR0 = XBR0|0x04; // Enable SMBus pins
XBR1 = XBR0|0x40; // Enable crossbar and weak pull-ups
P0 = 0xFF;
}
void smbusInit (void)
{
PCA0MD &= ~0x40; // WDTE = 0 (Disable watchdog
// timer)
OSCICN = 0x83; //选择内部时钟，分频系数是1
OSCICN |= 0x03; // Set internal oscillator to highest
// setting of 24500000
PORT_Init(); // Initialize Crossbar and GPIO
//Timer1_Init(); // Configure Timer1 for use
// with SMBus baud rate
//Timer3_Init (); // Configure Timer3 for use with
// SCL low timeout detect
SMBus_Init (); // Configure and enable SMBus
EIE1 |= 0x01; // Enable the SMBus interrupt
EA = 1; // Global interrupt enable
}
void SMBus_ISR (void) interrupt 7
{
if (ARBLOST == 0)
{
switch (SMB0CN & 0xF0) // Decode the SMBus status vector
{
// Slave Receiver: Start+Address received,收到起始信号和从机地址
case SMB_SRADD:
STA = 0; // Clear STA bit
if((SMB0DAT&0xFE) == (SLAVE_ADDR&0xFE)) // 地址过滤
{ // If the received address matches,
ACK = 1; // ACK the received slave address
if((SMB0DAT&0x01) == READ) // If the transfer is a master READ,
{
//smbDataRead(smbData[0],smbData[1]);
SMB0DAT = smbRecData;
LED_SMB = ~LED_SMB;
//smbIndex=0;
}
}
else // If received slave address does not
{ // match,
ACK = 0; // NACK received address
}
break;
// Slave Receiver: Data received，从机接收到数据
case SMB_SRDB:
smbData[smbIndex]=SMB0DAT;
smbIndex++;
if(smbIndex>=NUM_BYTES_RD)//3位收全了
{
//LED_SMB1 = ~LED_SMB1;
smbIndex =0;
smbReady=1;
sendMsgRequest =1;
//smbRecData = smbRecData|0x01;
}
ACK = 1; // ACK received data
// if(1==smbDataWrite(smbData[0],smbData[1]))
// SMB0DAT = smbRecData;
break;
// Slave Receiver: Stop received while either a Slave Receiver or
// Slave Transmitter，从机复位或者结束通信
case SMB_SRSTO:
STO = 0; // STO must be cleared by software when a STOP is detected as a slave
break;
case SMB_STDB: //从机发送完一个字节
if (ACK == 1) // If Master ACK's, send the next byte
{
SMB0DAT = 0xaa;
}
break;
// Slave Transmitter: Arbitration lost, Stop detected
// This state will only be entered on a bus error condition.
// In normal operation, the slave is no longer sending data or has
// data pending when a STOP is received from the master, so the TXMODE
// bit is cleared and the slave goes to the SRSTO state.
case SMB_STSTO: //丢失，直接复位
STO = 0; // STO must be cleared by software when a STOP is detected as a slave
break;
default: //其他情况直接复位
SMB0CF &= ~0x80; // Reset communication
SMB0CF |= 0x80;
STA = 0;
STO = 0;
ACK = 0;
break;
}
}
// ARBLOST = 1, Abort failed transfer
else
{
STA = 0;
STO = 0;
ACK = 0;
}
SI = 0; // Clear SMBus interrupt flag
}
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LZ现在模拟I2C从机，现在写入数据的时候，第2位到第8位的数据不能正常写入，其他位都是正常。
楼主
