I2C.rar_LPC1114_LPC1114 软件库_LPC1114 I2C_lpc1114 i2c_硬件I2C

/***************************************************************************** * i2c.c: I2C C file for NXP LPC11xx Family Microprocessors * * Copyright(C) 2008, NXP Semiconductor * All rights reserved. * * History * 2008.07.19 ver 1.00 Preliminary version, first Release * *****************************************************************************/ #include "LPC11xx.h" /* LPC11xx Peripheral Registers */ #include "type.h" #include "i2c.h" volatile uint32_t I2CMasterState = I2C_IDLE; volatile uint32_t I2CSlaveState = I2C_IDLE; volatile uint32_t I2CMode; volatile uint8_t I2CMasterBuffer[BUFSIZE]; volatile uint8_t I2CSlaveBuffer[BUFSIZE]; volatile uint32_t I2CCount = 0; volatile uint32_t I2CReadLength; volatile uint32_t I2CWriteLength; volatile uint32_t RdIndex = 0; volatile uint32_t WrIndex = 0; /* From device to device, the I2C communication protocol may vary, in the example below, the protocol uses repeated start to read data from or write to the device: For master read: the sequence is: STA,Addr(W),offset,RE-STA,Addr(r),data...STO for master write: the sequence is: STA,Addr(W),offset,RE-STA,Addr(w),data...STO Thus, in state 8, the address is always WRITE. in state 10, the address could be READ or WRITE depending on the I2C command. */ /***************************************************************************** ** Function name: I2C_IRQHandler ** ** Descriptions: I2C interrupt handler, deal with master mode only. ** ** parameters: None ** Returned value: None ** *****************************************************************************/ void I2C_IRQHandler(void) { uint8_t StatValue; /* this handler deals with master read and master write only */ StatValue = LPC_I2C->STAT; switch ( StatValue ) { case 0x08: /* A Start condition is issued. */ WrIndex = 0; LPC_I2C->DAT = I2CMasterBuffer[WrIndex++]; LPC_I2C->CONCLR = (I2CONCLR_SIC | I2CONCLR_STAC); I2CMasterState = I2C_STARTED; break; case 0x10: /* A repeated started is issued */ RdIndex = 0; /* Send SLA with R bit set, */ LPC_I2C->DAT = I2CMasterBuffer[WrIndex++]; LPC_I2C->CONCLR = (I2CONCLR_SIC | I2CONCLR_STAC); I2CMasterState = I2C_RESTARTED; break; case 0x18: /* Regardless, it's a ACK */ if ( I2CMasterState == I2C_STARTED ) { LPC_I2C->DAT = I2CMasterBuffer[WrIndex++]; I2CMasterState = DATA_ACK; } LPC_I2C->CONCLR = I2CONCLR_SIC; break; case 0x28: /* Data byte has been transmitted, regardless ACK or NACK */ case 0x30: if ( WrIndex < I2CWriteLength ) { LPC_I2C->DAT = I2CMasterBuffer[WrIndex++]; /* this should be the last one */ I2CMasterState = DATA_ACK; } else { if ( I2CReadLength != 0 ) { LPC_I2C->CONSET = I2CONSET_STA; /* Set Repeated-start flag */ I2CMasterState = I2C_REPEATED_START; } else { I2CMasterState = DATA_NACK; LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */ } } LPC_I2C->CONCLR = I2CONCLR_SIC; break; case 0x40: /* Master Receive, SLA_R has been sent */ if ( I2CReadLength == 1 ) { /* Will go to State 0x58 */ LPC_I2C->CONCLR = I2CONCLR_AAC; /* assert NACK after data is received */ } else { /* Will go to State 0x50 */ LPC_I2C->CONSET = I2CONSET_AA; /* assert ACK after data is received */ } LPC_I2C->CONCLR = I2CONCLR_SIC; break; case 0x50: /* Data byte has been received, regardless following ACK or NACK */ I2CSlaveBuffer[RdIndex++] = LPC_I2C->DAT; if ( RdIndex < I2CReadLength ) { I2CMasterState = DATA_ACK; LPC_I2C->CONSET = I2CONSET_AA; /* assert ACK after data is received */ } else { I2CMasterState = DATA_NACK; LPC_I2C->CONCLR = I2CONCLR_AAC; /* assert NACK on last byte */ } LPC_I2C->CONCLR = I2CONCLR_SIC; break; case 0x58: I2CSlaveBuffer[RdIndex++] = LPC_I2C->DAT; I2CMasterState = DATA_NACK; LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */ LPC_I2C->CONCLR = I2CONCLR_SIC; /* Clear SI flag */ break; case 0x20: /* regardless, it's a NACK */ case 0x48: LPC_I2C->CONCLR = I2CONCLR_SIC; I2CMasterState = DATA_NACK; break; case 0x38: /* Arbitration lost, in this example, we don't deal with multiple master situation */ default: LPC_I2C->CONCLR = I2CONCLR_SIC; break; } return; } /***************************************************************************** ** Function name: I2CStart ** ** Descriptions: Create I2C start condition, a timeout ** value is set if the I2C never gets started, ** and timed out. It's a fatal error. ** ** parameters: None ** Returned value: true or false, return false if timed out ** *****************************************************************************/ uint32_t I2CStart( void ) { uint32_t timeout = 0; uint32_t retVal = FALSE; /*--- Issue a start condition ---*/ LPC_I2C->CONSET = I2CONSET_STA; /* Set Start flag */ /*--- Wait until START transmitted ---*/ while( 1 ) { if ( I2CMasterState == I2C_STARTED ) { retVal = TRUE; break; } if ( timeout >= MAX_TIMEOUT ) { retVal = FALSE; break; } timeout++; } return( retVal ); } /***************************************************************************** ** Function name: I2CStop ** ** Descriptions: Set the I2C stop condition, if the routine ** never exit, it's a fatal bus error. ** ** parameters: None ** Returned value: true or never return ** *****************************************************************************/ uint32_t I2CStop( void ) { LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */ LPC_I2C->CONCLR = I2CONCLR_SIC; /* Clear SI flag */ /*--- Wait for STOP detected ---*/ while( LPC_I2C->CONSET & I2CONSET_STO ); return TRUE; } /***************************************************************************** ** Function name: I2CInit ** ** Descriptions: Initialize I2C controller ** ** parameters: I2c mode is either MASTER or SLAVE ** Returned value: true or false, return false if the I2C ** interrupt handler was not installed correctly ** *****************************************************************************/ uint32_t I2CInit( uint32_t I2cMode ) { /* It seems to be bit0 is for I2C, different from UM. To be retested along with SSP reset. SSP and I2C reset are overlapped, a known bug, for now, both SSP and I2C use bit 0 for reset enable. Once the problem is fixed, change to "#if 1". */ #if 1 LPC_SYSCON->PRESETCTRL |= (0x1<<1); #else LPC_SYSCON->PRESETCTRL |= (0x1<<0); #endif LPC_SYSCON->SYSAHBCLKCTRL |= (1<<5); LPC_IOCON->PIO0_4 &= ~0x3F; /* I2C I/O config */ LPC_IOCON->PIO0_4 |= 0x01; /* I2C SCL */ LPC_IOCON->PIO0_5 &= ~0x3F; LPC_IOCON->PIO0_5 |= 0x01; /* I2C SDA */ /*--- Clear flags ---*/ LPC_I2C->CONCLR = I2CONCLR_AAC | I2CONCLR_SIC | I2CONCLR_STAC | I2CONCLR_I2ENC; /*--- Reset registers ---*/ #if FAST_MODE_PLUS LPC_IOCON->PIO0_4 |= (0x1<<9); LPC_IOCON->PIO0_5 |= (0x1<<9); LPC_I2C->SCLL = I2SCLL_HS_SCLL; LPC_I2C->SCLH = I2SCLH_HS_SCLH; #else LPC_I2C->SCLL = I2SCLL_SCLL; LPC_I2C->SCLH = I2SCLH_SCLH; #endif if ( I2cMode == I2CSLAVE ) { LPC_I2C->ADR0 = PCF8594_ADDR; } /* Enable the I2C Interrupt */ NVIC_EnableIRQ(I2C_IRQn); LPC_I2C->CONSET = I2CONSET_I2EN; return( TRUE ); } /***************************************************************************** ** Function name: I2CEngine ** ** Descriptions: The routine to complete a I2C transaction ** from start to stop. All the intermitten ** steps are handled in the interrupt handler. ** Before this routine is called, the read ** length, write length, I2C master buffer, ** and I2C command fields need to be filled. ** see i2cmst.c for more details. ** ** param