| LPCOpen Platform v1.03 LPCOpen Platform for NXP LPC Microcontrollers

- Main Page
- Modules
- Data Structures
- Files
- Related Pages

- File List
- Globals

All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
adc_13xx.c
Go to the documentation of this file.
1 /*
2 * @brief LPC13xx 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 /* Get divider value for LPC1343 */
47 STATIC uint8_t getAdcClkDiv(bool burstMode, uint32_t adcRate, uint8_t clks)
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 4.5MHz.
55 A fully conversion requires (bits_accuracy+1) 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 adcBlockFreq = Chip_Clock_GetSystemClockRate();
60 #if defined(CHIP_LPC1347)
61 fullAdcRate = adcRate * 31;
62 if (clks == ADC_10BITS) {
63 fullAdcRate /= 2;
64 }
65
66 #else
67 if (burstMode) {
68 fullAdcRate = adcRate * clks;
69 }
70 else {
71 fullAdcRate = adcRate * 11;
72 }
73 #endif
74
75 /* Get the round value by fomular: (2*A + B)/(2*B) */
76 div = ((adcBlockFreq * 2 + fullAdcRate) / (fullAdcRate * 2)) - 1;
77 return div;
78 }
79
80 /*****************************************************************************
81 * Public functions
82 ****************************************************************************/
83
84 /* Shutdown ADC */
85 void Chip_ADC_DeInit(LPC_ADC_T *pADC)
86 {
87 IP_ADC_DeInit(pADC);
88
89 /* Enable ADC clocking and IO config pins are enabled in Channel enable cmd */
90 Chip_Clock_DisablePeriphClock(SYSCTL_CLOCK_ADC);
91
92 /* Disable power to the ADC block. */
93 Chip_SYSCTL_PowerDown(SYSCTL_POWERDOWN_ADC_PD);
94 }
95
96 /* Initialize the ADC peripheral and the ADC setup structure to default value */
97 void Chip_ADC_Init(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup)
98 {
99 uint8_t div;
100 /* Enable power to the ADC block. */
101 Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_ADC_PD);
102
103 /* Enable ADC clocking and IO config pins are enabled in Channel enable cmd */
104 Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_ADC);
105
106 #if defined(CHIP_LPC1347)
107 ADCSetup->adcRate = 500000;
108 ADCSetup->bitsAccuracy = ADC_12BITS;
109 ADCSetup->burstMode = false;
110 div = getAdcClkDiv(false, 500000, ADC_12BITS);
111 IP_ADC_Init(pADC, div, 0, ADC_CR_LPWRMODE);
112
113 #else
114 ADCSetup->adcRate = 400000;
115 ADCSetup->bitsAccuracy = ADC_10BITS;
116 ADCSetup->burstMode = false;
117 div = getAdcClkDiv(false, 400000, 11);
118 IP_ADC_Init(pADC, div, ADC_10BITS, 0);
119 #endif
120 }
121
122 /* Select the mode starting the AD conversion */
123 void Chip_ADC_Set_StartMode(LPC_ADC_T *pADC, CHIP_ADC_START_MODE_T mode, CHIP_ADC_EDGE_CFG_T EdgeOption)
124 {
125 if ((mode != ADC_START_NOW) && (mode != ADC_NO_START)) {
126 IP_ADC_EdgeStartConfig(pADC, (uint8_t) EdgeOption);
127 }
128 IP_ADC_SetStartMode(pADC, (uint8_t) mode);
129 }
130
131 /* Set the ADC Sample rate */
132 void Chip_ADC_Set_SampleRate(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup, uint32_t rate)
133 {
134 uint8_t div;
135
136 ADCSetup->adcRate = rate;
137 #if defined(CHIP_LPC1347)
138 div = getAdcClkDiv(ADCSetup->burstMode, rate, ADCSetup->bitsAccuracy);
139 if (ADCSetup->bitsAccuracy == ADC_10BITS) {
140 IP_ADC_Init(pADC, div, ADCSetup->bitsAccuracy, ADC_CR_LPWRMODE | ADC_CR_MODE10BIT);
141 }
142 else {
143 IP_ADC_Init(pADC, div, ADCSetup->bitsAccuracy, ADC_CR_LPWRMODE);
144 }
145
146 #else
147 div = getAdcClkDiv(ADCSetup->burstMode, rate, (11 - ADCSetup->bitsAccuracy));
148 IP_ADC_Init(pADC, div, ADCSetup->bitsAccuracy, 0);
149 #endif
150
151 }
152
153 /* Set the ADC accuracy bits */
154 void Chip_ADC_Set_Resolution(LPC_ADC_T *pADC, ADC_Clock_Setup_T *ADCSetup, CHIP_ADC_RESOLUTION_T resolution)
155 {
156 ADCSetup->bitsAccuracy = resolution;
157 Chip_ADC_Set_SampleRate(pADC, ADCSetup, ADCSetup->adcRate);
158 }
159
160 /* Enable or disable the ADC channel on ADC peripheral */
161 void Chip_ADC_Channel_Enable_Cmd(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, FunctionalState NewState)
162 {
163 IP_ADC_SetChannelNumber(pADC, channel, NewState);
164 }
165
166 /* Enable burst mode */
167 void Chip_ADC_Burst_Cmd(LPC_ADC_T *pADC, FunctionalState NewState)
168 {
169 IP_ADC_SetStartMode(pADC, ADC_NO_START);
170 IP_ADC_SetBurstMode(pADC, NewState);
171 }
172
173 /* Read the ADC value and convert it to 8bits value */
174 Status Chip_ADC_Read_Byte(LPC_ADC_T *pADC, CHIP_ADC_CHANNEL_T channel, uint8_t *data)
175 {
176 uint16_t temp;
177 Status rt;
178
179 rt = IP_ADC_Get_Val(pADC, channel, &temp);
180 *data = (uint8_t) temp;
181
182 return rt;
183 }