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adc_17xx_40xx.c
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1 /*
2 * @brief LPC17xx/40xx ADC conversion driver
3 *
4 * @note
5 * Copyright(C) NXP Semiconductors, 2012
6 * All rights reserved.
7 *
8 * @par
9 * Software that is described herein is for illustrative purposes only
10 * which provides customers with programming information regarding the
11 * LPC products. This software is supplied "AS IS" without any warranties of
12 * any kind, and NXP Semiconductors and its licensor disclaim any and
13 * all warranties, express or implied, including all implied warranties of
14 * merchantability, fitness for a particular purpose and non-infringement of
15 * intellectual property rights. NXP Semiconductors assumes no responsibility
16 * or liability for the use of the software, conveys no license or rights under any
17 * patent, copyright, mask work right, or any other intellectual property rights in
18 * or to any products. NXP Semiconductors reserves the right to make changes
19 * in the software without notification. NXP Semiconductors also makes no
20 * representation or warranty that such application will be suitable for the
21 * specified use without further testing or modification.
22 *
23 * @par
24 * Permission to use, copy, modify, and distribute this software and its
25 * documentation is hereby granted, under NXP Semiconductors' and its
26 * licensor's relevant copyrights in the software, without fee, provided that it
27 * is used in conjunction with NXP Semiconductors microcontrollers. This
28 * copyright, permission, and disclaimer notice must appear in all copies of
29 * this code.
30 */
31
32 #include "chip.h"
33
34 /*****************************************************************************
35 * Private types/enumerations/variables
36 ****************************************************************************/
37
38 /*****************************************************************************
39 * Public types/enumerations/variables
40 ****************************************************************************/
41
42 /*****************************************************************************
43 * Private functions
44 ****************************************************************************/
45
46 /* Get divider value for */
47 STATIC uint8_t getAdcClkDiv(uint32_t adcRate)
48 {
49 uint32_t adcBlockFreq;
50 uint32_t fullAdcRate;
51 uint8_t div;
52
53 /* The APB clock (PCLK_ADC0) is divided by (CLKDIV+1) to produce the clock for
54 * A/D converter, which should be less than or equal to 12.4MHz.
55 * A fully conversion requires 31 of these clocks.
56 * ADC clock = PCLK_ADC0 / (CLKDIV + 1);
57 * ADC rate = ADC clock / (the number of clocks required for each conversion);
58 */
59 #if defined(CHIP_LPC175X_6X)
60 adcBlockFreq = Chip_Clock_GetPeripheralClockRate(SYSCTL_PCLK_ADC);
61 fullAdcRate = adcRate * 65;
62 #else
63 adcBlockFreq = Chip_Clock_GetPeripheralClockRate();
64 fullAdcRate = adcRate * 31;
65 #endif
66
67 /* Get the round value by fomular: (2*A + B)/(2*B) */
68 div = ((adcBlockFreq * 2 + fullAdcRate) / (fullAdcRate * 2)) - 1;
69 return div;
70 }
71
72 /*****************************************************************************
73 * Public functions
74 ****************************************************************************/
75
76 /* Shutdown ADC */
77 void Chip_ADC_DeInit(LPC_ADC_T *pADC)
78 {
79 IP_ADC_DeInit(pADC);
80 Chip_Clock_DisablePeriphClock(SYSCTL_CLOCK_ADC);
81 }
82
83 /* Initialize the ADC peripheral and the ADC setup structure to default value */
84 void Chip_ADC_Init(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup)
85 {
86 uint8_t div;
87 /* Enable ADC clocking and get ADC clock rate */
88 Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_ADC);
89
90 ADCSetup->adcRate = ADC_MAX_SAMPLE_RATE;
91 ADCSetup->burstMode = false;
92 div = getAdcClkDiv(ADC_MAX_SAMPLE_RATE);
93 IP_ADC_Init(pADC, div, 0, ADC_CR_PDN);
94 }
95
96 /* Select the mode starting the AD conversion */
97 void Chip_ADC_Set_StartMode(LPC_ADC_T *pADC, CHIP_ADC_START_MODE_T mode, CHIP_ADC_EDGE_CFG_T EdgeOption)
98 {
99 if ((mode != ADC_START_NOW) && (mode != ADC_NO_START)) {
100 IP_ADC_EdgeStartConfig(pADC, (uint8_t) EdgeOption);
101 }
102 IP_ADC_SetStartMode(pADC, (uint8_t) mode);
103 }
104
105 /* Set the ADC Sample rate */
106 void Chip_ADC_Set_SampleRate(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup, uint32_t rate)
107 {
108 uint8_t div;
109 ADCSetup->adcRate = rate;
110 div = getAdcClkDiv(rate);
111 IP_ADC_Init(pADC, div, 0, ADC_CR_PDN);
112
113 }
114
115 /* Enable or disable the ADC channel on ADC peripheral */
116 void Chip_ADC_Channel_Enable_Cmd(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, FunctionalState NewState)
117 {
118 IP_ADC_SetChannelNumber(pADC, channel, NewState);
119 }
120
121 /* Enable burst mode */
122 void Chip_ADC_Burst_Cmd(LPC_ADC_T *pADC, FunctionalState NewState)
123 {
124 IP_ADC_SetStartMode(pADC, ADC_NO_START);
125 IP_ADC_SetBurstMode(pADC, NewState);
126 }
127
128 /* Read the ADC value and convert it to 8bits value */
129 Status Chip_ADC_Read_Byte(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, uint8_t *data)
130 {
131 uint16_t temp;
132 Status rt;
133
134 rt = IP_ADC_Get_Val(pADC, channel, &temp);
135 *data = (uint8_t) temp;
136
137 return rt;
138 }