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adc_18xx_43xx.c
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1 /*
2 * @brief LPC18xx/43xx A/D 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 /* Returns the clock for the selected ADC */
47 STATIC CHIP_CCU_CLK_T Chip_ADC_GetClk(LPC_ADC_T *pADC)
48 {
49 CHIP_CCU_CLK_T adcclk;
50
51 if (pADC == LPC_ADC0) {
52 adcclk = CLK_APB3_ADC0;
53 }
54 else {
55 adcclk = CLK_APB3_ADC1;
56 }
57
58 return adcclk;
59 }
60
61 /* Get divider value */
62 STATIC uint8_t getAdcClkDiv(LPC_ADC_T *pADC, bool burstMode, uint32_t adcRate,uint8_t clks)
63 {
64 uint32_t adcBlockFreq;
65 uint32_t fullAdcRate;
66 uint8_t div;
67
68 /* The APB clock (PCLK_ADC0) is divided by (CLKDIV+1) to produce the clock for
69 A/D converter, which should be less than or equal to 4.5MHz.
70 A fully conversion requires (bits_accuracy+1) of these clocks.
71 ADC Clock = PCLK_ADC0 / (CLKDIV + 1);
72 ADC rate = ADC clock / (the number of clocks required for each conversion);
73 */
74 adcBlockFreq = Chip_Clock_GetRate(Chip_ADC_GetClk(pADC));
75 if(burstMode)
76 fullAdcRate = adcRate * clks;
77 else
78 fullAdcRate = adcRate * 11;
79
80 /* Get the round value by fomular: (2*A + B)/(2*B) */
81 div = ((adcBlockFreq * 2 + fullAdcRate) / (fullAdcRate * 2)) - 1;
82 return div;
83 }
84
85
86 /*****************************************************************************
87 * Public functions
88 ****************************************************************************/
89
90 /* Shutdown ADC */
91 void Chip_ADC_DeInit(LPC_ADC_T *pADC)
92 {
93 IP_ADC_DeInit(pADC);
94 Chip_Clock_Disable(Chip_ADC_GetClk(pADC));
95 }
96
97 /* Initialize the ADC peripheral and the ADC setup structure to default value */
98 void Chip_ADC_Init(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup)
99 {
100 uint8_t div;
101 CHIP_CCU_CLK_T adcclk = Chip_ADC_GetClk(pADC);
102
103 /* Enable ADC clocking */
104 Chip_Clock_EnableOpts(adcclk, true, true, 1);
105
106 ADCSetup->adcRate = 400000;
107 ADCSetup->bitsAccuracy = ADC_10BITS;
108 ADCSetup->burstMode = false;
109 div = getAdcClkDiv(pADC, false, 400000, 11);
110 IP_ADC_Init(pADC, div, ADC_10BITS, ADC_CR_PDN);
111 }
112
113 /* Select the mode starting the AD conversion */
114 void Chip_ADC_Set_StartMode(LPC_ADC_T *pADC, CHIP_ADC_START_MODE_T mode, CHIP_ADC_EDGE_CFG_T EdgeOption)
115 {
116 if ((mode != ADC_START_NOW) && (mode != ADC_NO_START)) {
117 IP_ADC_EdgeStartConfig(pADC, (uint8_t) EdgeOption);
118 }
119 IP_ADC_SetStartMode(pADC, (uint8_t) mode);
120 }
121
122 /* Set the ADC Sample rate */
123 void Chip_ADC_Set_SampleRate(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup, uint32_t rate)
124 {
125 uint8_t div;
126 ADCSetup->adcRate = rate;
127 div = getAdcClkDiv(pADC, ADCSetup->burstMode, rate, (11- ADCSetup->bitsAccuracy));
128 IP_ADC_Init(pADC, div, ADCSetup->bitsAccuracy, ADC_CR_PDN);
129 }
130
131 /* Set the ADC accuracy bits */
132 void Chip_ADC_Set_Resolution(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup, CHIP_ADC_RESOLUTION_T resolution)
133 {
134 ADCSetup->bitsAccuracy = resolution;
135 Chip_ADC_Set_SampleRate(pADC, ADCSetup,ADCSetup->adcRate);
136 }
137
138 /* Enable or disable the ADC channel on ADC peripheral */
139 void Chip_ADC_Channel_Enable_Cmd(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, FunctionalState NewState)
140 {
141 IP_ADC_SetChannelNumber(pADC, channel, NewState);
142 }
143
144 /* Enable burst mode */
145 void Chip_ADC_Burst_Cmd(LPC_ADC_T *pADC, FunctionalState NewState)
146 {
147 IP_ADC_SetStartMode(pADC, ADC_NO_START);
148 IP_ADC_SetBurstMode(pADC, NewState);
149 }
150
151 /* Read the ADC value and convert it to 8bits value */
152 Status Chip_ADC_Read_Byte(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, uint8_t *data)
153 {
154 uint16_t temp;
155 Status rt;
156
157 rt = IP_ADC_Get_Val(pADC, channel, &temp);
158 *data = (uint8_t) temp;
159
160 return rt;
161 }