ADC.rar_lpc23xx adc

/***************************************************************************** * adc.c: ADC module file for NXP LPC23xx Family Microprocessors * * Copyright(C) 2006, NXP Semiconductor * All rights reserved. * * History * 2006.08.15 ver 1.00 Prelimnary version, first Release * ******************************************************************************/ #include "LPC23xx.h" /* LPC23xx definitions */ #include "type.h" #include "irq.h" #include "target.h" #include "adc.h" volatile DWORD ADC0Value[ADC_NUM]; volatile DWORD ADC0IntDone = 0; #if ADC_INTERRUPT_FLAG /****************************************************************************** ** Function name: ADC0Handler ** ** Descriptions: ADC0 interrupt handler ** ** parameters: None ** Returned value: None ** ******************************************************************************/ void ADC0Handler (void) __irq { DWORD regVal; IENABLE; /* handles nested interrupt */ regVal = AD0STAT; /* Read ADC will clear the interrupt */ if ( regVal & 0x0000FF00 ) /* check OVERRUN error first */ { regVal = (regVal & 0x0000FF00) >> 0x08; /* if overrun, just read ADDR to clear */ /* regVal variable has been reused. */ switch ( regVal ) { case 0x01: regVal = AD0DR0; break; case 0x02: regVal = AD0DR1; break; case 0x04: regVal = AD0DR2; break; case 0x08: regVal = AD0DR3; break; case 0x10: regVal = AD0DR4; break; case 0x20: regVal = AD0DR5; break; case 0x40: regVal = AD0DR6; break; case 0x80: regVal = AD0DR7; break; default: break; } AD0CR &= 0xF8FFFFFF; /* stop ADC now */ ADC0IntDone = 1; return; } if ( regVal & ADC_ADINT ) { switch ( regVal & 0xFF ) /* check DONE bit */ { case 0x01: ADC0Value[0] = ( AD0DR0 >> 6 ) & 0x3FF; break; case 0x02: ADC0Value[1] = ( AD0DR1 >> 6 ) & 0x3FF; break; case 0x04: ADC0Value[2] = ( AD0DR2 >> 6 ) & 0x3FF; break; case 0x08: ADC0Value[3] = ( AD0DR3 >> 6 ) & 0x3FF; break; case 0x10: ADC0Value[4] = ( AD0DR4 >> 6 ) & 0x3FF; break; case 0x20: ADC0Value[5] = ( AD0DR5 >> 6 ) & 0x3FF; break; case 0x40: ADC0Value[6] = ( AD0DR6 >> 6 ) & 0x3FF; break; case 0x80: ADC0Value[7] = ( AD0DR7 >> 6 ) & 0x3FF; break; default: break; } AD0CR &= 0xF8FFFFFF; /* stop ADC now */ ADC0IntDone = 1; } IDISABLE; VICVectAddr = 0; /* Acknowledge Interrupt */ } #endif /***************************************************************************** ** Function name: ADCInit ** ** Descriptions: initialize ADC channel ** ** parameters: ADC clock rate ** Returned value: true or false ** *****************************************************************************/ DWORD ADCInit( DWORD ADC_Clk ) { /* Enable CLOCK into ADC controller */ PCONP |= (1 << 12); /* all the related pins are set to ADC inputs, AD0.0~7 */ PINSEL0 |= 0x0F000000; /* P0.12~13, A0.6~7, function 11 */ PINSEL1 &= ~0x003FC000; /* P0.23~26, A0.0~3, function 01 */ PINSEL1 |= 0x00154000; PINSEL3 |= 0xF0000000; /* P1.30~31, A0.4~5, function 11 */ AD0CR = ( 0x01 << 0 ) | /* SEL=1,select channel 0~7 on ADC0 */ ( ( Fpclk / ADC_Clk - 1 ) << 8 ) | /* CLKDIV = Fpclk / 1000000 - 1 */ ( 0 << 16 ) | /* BURST = 0, no BURST, software controlled */ ( 0 << 17 ) | /* CLKS = 0, 11 clocks/10 bits */ ( 1 << 21 ) | /* PDN = 1, normal operation */ ( 0 << 22 ) | /* TEST1:0 = 00 */ ( 0 << 24 ) | /* START = 0 A/D conversion stops */ ( 0 << 27 ); /* EDGE = 0 (CAP/MAT singal falling,trigger A/D conversion) */ /* If POLLING, no need to do the following */ #if ADC_INTERRUPT_FLAG AD0INTEN = 0x1FF; /* Enable all interrupts */ if ( install_irq( ADC0_INT, (void *)ADC0Handler, HIGHEST_PRIORITY ) == FALSE ) { return (FALSE); } #endif return (TRUE); } /***************************************************************************** ** Function name: ADC0Read ** ** Descriptions: Read ADC0 channel ** ** parameters: Channel number ** Returned value: Value read, if interrupt driven, return channel # ** *****************************************************************************/ DWORD ADC0Read( BYTE channelNum ) { #if !ADC_INTERRUPT_FLAG DWORD regVal, ADC_Data; #endif /* channel number is 0 through 7 */ if ( channelNum >= ADC_NUM ) { channelNum = 0; /* reset channel number to 0 */ } AD0CR &= 0xFFFFFF00; AD0CR |= (1 << 24) | (1 << channelNum); /* switch channel,start A/D convert */ #if !ADC_INTERRUPT_FLAG while ( 1 ) /* wait until end of A/D convert */ { regVal = *(volatile unsigned long *)(AD0_BASE_ADDR + ADC_OFFSET + ADC_INDEX * channelNum); /* read result of A/D conversion */ if ( regVal & ADC_DONE ) { break; } } AD0CR &= 0xF8FFFFFF; /* stop ADC now */ if ( regVal & ADC_OVERRUN ) /* save data when it's not overrun, otherwise, return zero */ { return ( 0 ); } ADC_Data = ( regVal >> 6 ) & 0x3FF; return ( ADC_Data ); /* return A/D conversion value */ #else return ( channelNum ); /* if it's interrupt driven, the ADC reading is done inside the handler. so, return channel number */ #endif } /********************************************************************************* ** End Of File *********************************************************************************/