added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/emlib/src/em_dac.c@147:ba84b7dc41a7, 2016-09-10 (annotated)
- Committer:
- JojoS
- Date:
- Sat Sep 10 15:32:04 2016 +0000
- Revision:
- 147:ba84b7dc41a7
- Parent:
- 144:ef7eb2e8f9f7
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
<> | 144:ef7eb2e8f9f7 | 1 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 2 | * @file em_dac.c |
<> | 144:ef7eb2e8f9f7 | 3 | * @brief Digital to Analog Coversion (DAC) Peripheral API |
<> | 144:ef7eb2e8f9f7 | 4 | * @version 4.2.1 |
<> | 144:ef7eb2e8f9f7 | 5 | ******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 6 | * @section License |
<> | 144:ef7eb2e8f9f7 | 7 | * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b> |
<> | 144:ef7eb2e8f9f7 | 8 | ******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 9 | * |
<> | 144:ef7eb2e8f9f7 | 10 | * Permission is granted to anyone to use this software for any purpose, |
<> | 144:ef7eb2e8f9f7 | 11 | * including commercial applications, and to alter it and redistribute it |
<> | 144:ef7eb2e8f9f7 | 12 | * freely, subject to the following restrictions: |
<> | 144:ef7eb2e8f9f7 | 13 | * |
<> | 144:ef7eb2e8f9f7 | 14 | * 1. The origin of this software must not be misrepresented; you must not |
<> | 144:ef7eb2e8f9f7 | 15 | * claim that you wrote the original software. |
<> | 144:ef7eb2e8f9f7 | 16 | * 2. Altered source versions must be plainly marked as such, and must not be |
<> | 144:ef7eb2e8f9f7 | 17 | * misrepresented as being the original software. |
<> | 144:ef7eb2e8f9f7 | 18 | * 3. This notice may not be removed or altered from any source distribution. |
<> | 144:ef7eb2e8f9f7 | 19 | * |
<> | 144:ef7eb2e8f9f7 | 20 | * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no |
<> | 144:ef7eb2e8f9f7 | 21 | * obligation to support this Software. Silicon Labs is providing the |
<> | 144:ef7eb2e8f9f7 | 22 | * Software "AS IS", with no express or implied warranties of any kind, |
<> | 144:ef7eb2e8f9f7 | 23 | * including, but not limited to, any implied warranties of merchantability |
<> | 144:ef7eb2e8f9f7 | 24 | * or fitness for any particular purpose or warranties against infringement |
<> | 144:ef7eb2e8f9f7 | 25 | * of any proprietary rights of a third party. |
<> | 144:ef7eb2e8f9f7 | 26 | * |
<> | 144:ef7eb2e8f9f7 | 27 | * Silicon Labs will not be liable for any consequential, incidental, or |
<> | 144:ef7eb2e8f9f7 | 28 | * special damages, or any other relief, or for any claim by any third party, |
<> | 144:ef7eb2e8f9f7 | 29 | * arising from your use of this Software. |
<> | 144:ef7eb2e8f9f7 | 30 | * |
<> | 144:ef7eb2e8f9f7 | 31 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 32 | |
<> | 144:ef7eb2e8f9f7 | 33 | #include "em_dac.h" |
<> | 144:ef7eb2e8f9f7 | 34 | #if defined(DAC_COUNT) && (DAC_COUNT > 0) |
<> | 144:ef7eb2e8f9f7 | 35 | #include "em_cmu.h" |
<> | 144:ef7eb2e8f9f7 | 36 | #include "em_assert.h" |
<> | 144:ef7eb2e8f9f7 | 37 | #include "em_bus.h" |
<> | 144:ef7eb2e8f9f7 | 38 | |
<> | 144:ef7eb2e8f9f7 | 39 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 40 | * @addtogroup EM_Library |
<> | 144:ef7eb2e8f9f7 | 41 | * @{ |
<> | 144:ef7eb2e8f9f7 | 42 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 43 | |
<> | 144:ef7eb2e8f9f7 | 44 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 45 | * @addtogroup DAC |
<> | 144:ef7eb2e8f9f7 | 46 | * @brief Digital to Analog Coversion (DAC) Peripheral API |
<> | 144:ef7eb2e8f9f7 | 47 | * @{ |
<> | 144:ef7eb2e8f9f7 | 48 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 49 | |
<> | 144:ef7eb2e8f9f7 | 50 | /******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 51 | ******************************* DEFINES *********************************** |
<> | 144:ef7eb2e8f9f7 | 52 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 53 | |
<> | 144:ef7eb2e8f9f7 | 54 | /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */ |
<> | 144:ef7eb2e8f9f7 | 55 | |
<> | 144:ef7eb2e8f9f7 | 56 | /** Validation of DAC channel for assert statements. */ |
<> | 144:ef7eb2e8f9f7 | 57 | #define DAC_CH_VALID(ch) ((ch) <= 1) |
<> | 144:ef7eb2e8f9f7 | 58 | |
<> | 144:ef7eb2e8f9f7 | 59 | /** Max DAC clock */ |
<> | 144:ef7eb2e8f9f7 | 60 | #define DAC_MAX_CLOCK 1000000 |
<> | 144:ef7eb2e8f9f7 | 61 | |
<> | 144:ef7eb2e8f9f7 | 62 | /** @endcond */ |
<> | 144:ef7eb2e8f9f7 | 63 | |
<> | 144:ef7eb2e8f9f7 | 64 | /******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 65 | ************************** GLOBAL FUNCTIONS ******************************* |
<> | 144:ef7eb2e8f9f7 | 66 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 67 | |
<> | 144:ef7eb2e8f9f7 | 68 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 69 | * @brief |
<> | 144:ef7eb2e8f9f7 | 70 | * Enable/disable DAC channel. |
<> | 144:ef7eb2e8f9f7 | 71 | * |
<> | 144:ef7eb2e8f9f7 | 72 | * @param[in] dac |
<> | 144:ef7eb2e8f9f7 | 73 | * Pointer to DAC peripheral register block. |
<> | 144:ef7eb2e8f9f7 | 74 | * |
<> | 144:ef7eb2e8f9f7 | 75 | * @param[in] ch |
<> | 144:ef7eb2e8f9f7 | 76 | * Channel to enable/disable. |
<> | 144:ef7eb2e8f9f7 | 77 | * |
<> | 144:ef7eb2e8f9f7 | 78 | * @param[in] enable |
<> | 144:ef7eb2e8f9f7 | 79 | * true to enable DAC channel, false to disable. |
<> | 144:ef7eb2e8f9f7 | 80 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 81 | void DAC_Enable(DAC_TypeDef *dac, unsigned int ch, bool enable) |
<> | 144:ef7eb2e8f9f7 | 82 | { |
<> | 144:ef7eb2e8f9f7 | 83 | volatile uint32_t *reg; |
<> | 144:ef7eb2e8f9f7 | 84 | |
<> | 144:ef7eb2e8f9f7 | 85 | EFM_ASSERT(DAC_REF_VALID(dac)); |
<> | 144:ef7eb2e8f9f7 | 86 | EFM_ASSERT(DAC_CH_VALID(ch)); |
<> | 144:ef7eb2e8f9f7 | 87 | |
<> | 144:ef7eb2e8f9f7 | 88 | if (!ch) |
<> | 144:ef7eb2e8f9f7 | 89 | { |
<> | 144:ef7eb2e8f9f7 | 90 | reg = &(dac->CH0CTRL); |
<> | 144:ef7eb2e8f9f7 | 91 | } |
<> | 144:ef7eb2e8f9f7 | 92 | else |
<> | 144:ef7eb2e8f9f7 | 93 | { |
<> | 144:ef7eb2e8f9f7 | 94 | reg = &(dac->CH1CTRL); |
<> | 144:ef7eb2e8f9f7 | 95 | } |
<> | 144:ef7eb2e8f9f7 | 96 | |
<> | 144:ef7eb2e8f9f7 | 97 | BUS_RegBitWrite(reg, _DAC_CH0CTRL_EN_SHIFT, enable); |
<> | 144:ef7eb2e8f9f7 | 98 | } |
<> | 144:ef7eb2e8f9f7 | 99 | |
<> | 144:ef7eb2e8f9f7 | 100 | |
<> | 144:ef7eb2e8f9f7 | 101 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 102 | * @brief |
<> | 144:ef7eb2e8f9f7 | 103 | * Initialize DAC. |
<> | 144:ef7eb2e8f9f7 | 104 | * |
<> | 144:ef7eb2e8f9f7 | 105 | * @details |
<> | 144:ef7eb2e8f9f7 | 106 | * Initializes common parts for both channels. In addition, channel control |
<> | 144:ef7eb2e8f9f7 | 107 | * configuration must be done, please refer to DAC_InitChannel(). |
<> | 144:ef7eb2e8f9f7 | 108 | * |
<> | 144:ef7eb2e8f9f7 | 109 | * @note |
<> | 144:ef7eb2e8f9f7 | 110 | * This function will disable both channels prior to configuration. |
<> | 144:ef7eb2e8f9f7 | 111 | * |
<> | 144:ef7eb2e8f9f7 | 112 | * @param[in] dac |
<> | 144:ef7eb2e8f9f7 | 113 | * Pointer to DAC peripheral register block. |
<> | 144:ef7eb2e8f9f7 | 114 | * |
<> | 144:ef7eb2e8f9f7 | 115 | * @param[in] init |
<> | 144:ef7eb2e8f9f7 | 116 | * Pointer to DAC initialization structure. |
<> | 144:ef7eb2e8f9f7 | 117 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 118 | void DAC_Init(DAC_TypeDef *dac, const DAC_Init_TypeDef *init) |
<> | 144:ef7eb2e8f9f7 | 119 | { |
<> | 144:ef7eb2e8f9f7 | 120 | uint32_t tmp; |
<> | 144:ef7eb2e8f9f7 | 121 | |
<> | 144:ef7eb2e8f9f7 | 122 | EFM_ASSERT(DAC_REF_VALID(dac)); |
<> | 144:ef7eb2e8f9f7 | 123 | |
<> | 144:ef7eb2e8f9f7 | 124 | /* Make sure both channels are disabled. */ |
<> | 144:ef7eb2e8f9f7 | 125 | BUS_RegBitWrite(&(dac->CH0CTRL), _DAC_CH0CTRL_EN_SHIFT, 0); |
<> | 144:ef7eb2e8f9f7 | 126 | BUS_RegBitWrite(&(dac->CH1CTRL), _DAC_CH0CTRL_EN_SHIFT, 0); |
<> | 144:ef7eb2e8f9f7 | 127 | |
<> | 144:ef7eb2e8f9f7 | 128 | /* Load proper calibration data depending on selected reference */ |
<> | 144:ef7eb2e8f9f7 | 129 | switch (init->reference) |
<> | 144:ef7eb2e8f9f7 | 130 | { |
<> | 144:ef7eb2e8f9f7 | 131 | case dacRef2V5: |
<> | 144:ef7eb2e8f9f7 | 132 | dac->CAL = DEVINFO->DAC0CAL1; |
<> | 144:ef7eb2e8f9f7 | 133 | break; |
<> | 144:ef7eb2e8f9f7 | 134 | |
<> | 144:ef7eb2e8f9f7 | 135 | case dacRefVDD: |
<> | 144:ef7eb2e8f9f7 | 136 | dac->CAL = DEVINFO->DAC0CAL2; |
<> | 144:ef7eb2e8f9f7 | 137 | break; |
<> | 144:ef7eb2e8f9f7 | 138 | |
<> | 144:ef7eb2e8f9f7 | 139 | default: /* 1.25V */ |
<> | 144:ef7eb2e8f9f7 | 140 | dac->CAL = DEVINFO->DAC0CAL0; |
<> | 144:ef7eb2e8f9f7 | 141 | break; |
<> | 144:ef7eb2e8f9f7 | 142 | } |
<> | 144:ef7eb2e8f9f7 | 143 | |
<> | 144:ef7eb2e8f9f7 | 144 | tmp = ((uint32_t)(init->refresh) << _DAC_CTRL_REFRSEL_SHIFT) |
<> | 144:ef7eb2e8f9f7 | 145 | | (((uint32_t)(init->prescale) << _DAC_CTRL_PRESC_SHIFT) |
<> | 144:ef7eb2e8f9f7 | 146 | & _DAC_CTRL_PRESC_MASK) |
<> | 144:ef7eb2e8f9f7 | 147 | | ((uint32_t)(init->reference) << _DAC_CTRL_REFSEL_SHIFT) |
<> | 144:ef7eb2e8f9f7 | 148 | | ((uint32_t)(init->outMode) << _DAC_CTRL_OUTMODE_SHIFT) |
<> | 144:ef7eb2e8f9f7 | 149 | | ((uint32_t)(init->convMode) << _DAC_CTRL_CONVMODE_SHIFT); |
<> | 144:ef7eb2e8f9f7 | 150 | |
<> | 144:ef7eb2e8f9f7 | 151 | if (init->ch0ResetPre) |
<> | 144:ef7eb2e8f9f7 | 152 | { |
<> | 144:ef7eb2e8f9f7 | 153 | tmp |= DAC_CTRL_CH0PRESCRST; |
<> | 144:ef7eb2e8f9f7 | 154 | } |
<> | 144:ef7eb2e8f9f7 | 155 | |
<> | 144:ef7eb2e8f9f7 | 156 | if (init->outEnablePRS) |
<> | 144:ef7eb2e8f9f7 | 157 | { |
<> | 144:ef7eb2e8f9f7 | 158 | tmp |= DAC_CTRL_OUTENPRS; |
<> | 144:ef7eb2e8f9f7 | 159 | } |
<> | 144:ef7eb2e8f9f7 | 160 | |
<> | 144:ef7eb2e8f9f7 | 161 | if (init->sineEnable) |
<> | 144:ef7eb2e8f9f7 | 162 | { |
<> | 144:ef7eb2e8f9f7 | 163 | tmp |= DAC_CTRL_SINEMODE; |
<> | 144:ef7eb2e8f9f7 | 164 | } |
<> | 144:ef7eb2e8f9f7 | 165 | |
<> | 144:ef7eb2e8f9f7 | 166 | if (init->diff) |
<> | 144:ef7eb2e8f9f7 | 167 | { |
<> | 144:ef7eb2e8f9f7 | 168 | tmp |= DAC_CTRL_DIFF; |
<> | 144:ef7eb2e8f9f7 | 169 | } |
<> | 144:ef7eb2e8f9f7 | 170 | |
<> | 144:ef7eb2e8f9f7 | 171 | dac->CTRL = tmp; |
<> | 144:ef7eb2e8f9f7 | 172 | } |
<> | 144:ef7eb2e8f9f7 | 173 | |
<> | 144:ef7eb2e8f9f7 | 174 | |
<> | 144:ef7eb2e8f9f7 | 175 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 176 | * @brief |
<> | 144:ef7eb2e8f9f7 | 177 | * Initialize DAC channel. |
<> | 144:ef7eb2e8f9f7 | 178 | * |
<> | 144:ef7eb2e8f9f7 | 179 | * @param[in] dac |
<> | 144:ef7eb2e8f9f7 | 180 | * Pointer to DAC peripheral register block. |
<> | 144:ef7eb2e8f9f7 | 181 | * |
<> | 144:ef7eb2e8f9f7 | 182 | * @param[in] init |
<> | 144:ef7eb2e8f9f7 | 183 | * Pointer to DAC initialization structure. |
<> | 144:ef7eb2e8f9f7 | 184 | * |
<> | 144:ef7eb2e8f9f7 | 185 | * @param[in] ch |
<> | 144:ef7eb2e8f9f7 | 186 | * Channel number to initialize. |
<> | 144:ef7eb2e8f9f7 | 187 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 188 | void DAC_InitChannel(DAC_TypeDef *dac, |
<> | 144:ef7eb2e8f9f7 | 189 | const DAC_InitChannel_TypeDef *init, |
<> | 144:ef7eb2e8f9f7 | 190 | unsigned int ch) |
<> | 144:ef7eb2e8f9f7 | 191 | { |
<> | 144:ef7eb2e8f9f7 | 192 | uint32_t tmp; |
<> | 144:ef7eb2e8f9f7 | 193 | |
<> | 144:ef7eb2e8f9f7 | 194 | EFM_ASSERT(DAC_REF_VALID(dac)); |
<> | 144:ef7eb2e8f9f7 | 195 | EFM_ASSERT(DAC_CH_VALID(ch)); |
<> | 144:ef7eb2e8f9f7 | 196 | |
<> | 144:ef7eb2e8f9f7 | 197 | tmp = (uint32_t)(init->prsSel) << _DAC_CH0CTRL_PRSSEL_SHIFT; |
<> | 144:ef7eb2e8f9f7 | 198 | |
<> | 144:ef7eb2e8f9f7 | 199 | if (init->enable) |
<> | 144:ef7eb2e8f9f7 | 200 | { |
<> | 144:ef7eb2e8f9f7 | 201 | tmp |= DAC_CH0CTRL_EN; |
<> | 144:ef7eb2e8f9f7 | 202 | } |
<> | 144:ef7eb2e8f9f7 | 203 | |
<> | 144:ef7eb2e8f9f7 | 204 | if (init->prsEnable) |
<> | 144:ef7eb2e8f9f7 | 205 | { |
<> | 144:ef7eb2e8f9f7 | 206 | tmp |= DAC_CH0CTRL_PRSEN; |
<> | 144:ef7eb2e8f9f7 | 207 | } |
<> | 144:ef7eb2e8f9f7 | 208 | |
<> | 144:ef7eb2e8f9f7 | 209 | if (init->refreshEnable) |
<> | 144:ef7eb2e8f9f7 | 210 | { |
<> | 144:ef7eb2e8f9f7 | 211 | tmp |= DAC_CH0CTRL_REFREN; |
<> | 144:ef7eb2e8f9f7 | 212 | } |
<> | 144:ef7eb2e8f9f7 | 213 | |
<> | 144:ef7eb2e8f9f7 | 214 | if (ch) |
<> | 144:ef7eb2e8f9f7 | 215 | { |
<> | 144:ef7eb2e8f9f7 | 216 | dac->CH1CTRL = tmp; |
<> | 144:ef7eb2e8f9f7 | 217 | } |
<> | 144:ef7eb2e8f9f7 | 218 | else |
<> | 144:ef7eb2e8f9f7 | 219 | { |
<> | 144:ef7eb2e8f9f7 | 220 | dac->CH0CTRL = tmp; |
<> | 144:ef7eb2e8f9f7 | 221 | } |
<> | 144:ef7eb2e8f9f7 | 222 | } |
<> | 144:ef7eb2e8f9f7 | 223 | |
<> | 144:ef7eb2e8f9f7 | 224 | |
<> | 144:ef7eb2e8f9f7 | 225 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 226 | * @brief |
<> | 144:ef7eb2e8f9f7 | 227 | * Set the output signal of a DAC channel to a given value. |
<> | 144:ef7eb2e8f9f7 | 228 | * |
<> | 144:ef7eb2e8f9f7 | 229 | * @details |
<> | 144:ef7eb2e8f9f7 | 230 | * This function sets the output signal of a DAC channel by writing @p value |
<> | 144:ef7eb2e8f9f7 | 231 | * to the corresponding CHnDATA register. |
<> | 144:ef7eb2e8f9f7 | 232 | * |
<> | 144:ef7eb2e8f9f7 | 233 | * @param[in] dac |
<> | 144:ef7eb2e8f9f7 | 234 | * Pointer to DAC peripheral register block. |
<> | 144:ef7eb2e8f9f7 | 235 | * |
<> | 144:ef7eb2e8f9f7 | 236 | * @param[in] channel |
<> | 144:ef7eb2e8f9f7 | 237 | * Channel number to set output of. |
<> | 144:ef7eb2e8f9f7 | 238 | * |
<> | 144:ef7eb2e8f9f7 | 239 | * @param[in] value |
<> | 144:ef7eb2e8f9f7 | 240 | * Value to write to the channel output register CHnDATA. |
<> | 144:ef7eb2e8f9f7 | 241 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 242 | void DAC_ChannelOutputSet( DAC_TypeDef *dac, |
<> | 144:ef7eb2e8f9f7 | 243 | unsigned int channel, |
<> | 144:ef7eb2e8f9f7 | 244 | uint32_t value ) |
<> | 144:ef7eb2e8f9f7 | 245 | { |
<> | 144:ef7eb2e8f9f7 | 246 | switch(channel) |
<> | 144:ef7eb2e8f9f7 | 247 | { |
<> | 144:ef7eb2e8f9f7 | 248 | case 0: |
<> | 144:ef7eb2e8f9f7 | 249 | DAC_Channel0OutputSet(dac, value); |
<> | 144:ef7eb2e8f9f7 | 250 | break; |
<> | 144:ef7eb2e8f9f7 | 251 | case 1: |
<> | 144:ef7eb2e8f9f7 | 252 | DAC_Channel1OutputSet(dac, value); |
<> | 144:ef7eb2e8f9f7 | 253 | break; |
<> | 144:ef7eb2e8f9f7 | 254 | default: |
<> | 144:ef7eb2e8f9f7 | 255 | EFM_ASSERT(0); |
<> | 144:ef7eb2e8f9f7 | 256 | break; |
<> | 144:ef7eb2e8f9f7 | 257 | } |
<> | 144:ef7eb2e8f9f7 | 258 | } |
<> | 144:ef7eb2e8f9f7 | 259 | |
<> | 144:ef7eb2e8f9f7 | 260 | |
<> | 144:ef7eb2e8f9f7 | 261 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 262 | * @brief |
<> | 144:ef7eb2e8f9f7 | 263 | * Calculate prescaler value used to determine DAC clock. |
<> | 144:ef7eb2e8f9f7 | 264 | * |
<> | 144:ef7eb2e8f9f7 | 265 | * @details |
<> | 144:ef7eb2e8f9f7 | 266 | * The DAC clock is given by: HFPERCLK / (prescale ^ 2). If the requested |
<> | 144:ef7eb2e8f9f7 | 267 | * DAC frequency is low and the max prescaler value can not adjust the |
<> | 144:ef7eb2e8f9f7 | 268 | * actual DAC frequency lower than the requested DAC frequency, then the |
<> | 144:ef7eb2e8f9f7 | 269 | * max prescaler value is returned, resulting in a higher DAC frequency |
<> | 144:ef7eb2e8f9f7 | 270 | * than requested. |
<> | 144:ef7eb2e8f9f7 | 271 | * |
<> | 144:ef7eb2e8f9f7 | 272 | * @param[in] dacFreq DAC frequency wanted. The frequency will automatically |
<> | 144:ef7eb2e8f9f7 | 273 | * be adjusted to be below max allowed DAC clock. |
<> | 144:ef7eb2e8f9f7 | 274 | * |
<> | 144:ef7eb2e8f9f7 | 275 | * @param[in] hfperFreq Frequency in Hz of reference HFPER clock. Set to 0 to |
<> | 144:ef7eb2e8f9f7 | 276 | * use currently defined HFPER clock setting. |
<> | 144:ef7eb2e8f9f7 | 277 | * |
<> | 144:ef7eb2e8f9f7 | 278 | * @return |
<> | 144:ef7eb2e8f9f7 | 279 | * Prescaler value to use for DAC in order to achieve a clock value |
<> | 144:ef7eb2e8f9f7 | 280 | * <= @p dacFreq. |
<> | 144:ef7eb2e8f9f7 | 281 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 282 | uint8_t DAC_PrescaleCalc(uint32_t dacFreq, uint32_t hfperFreq) |
<> | 144:ef7eb2e8f9f7 | 283 | { |
<> | 144:ef7eb2e8f9f7 | 284 | uint32_t ret; |
<> | 144:ef7eb2e8f9f7 | 285 | |
<> | 144:ef7eb2e8f9f7 | 286 | /* Make sure selected DAC clock is below max value */ |
<> | 144:ef7eb2e8f9f7 | 287 | if (dacFreq > DAC_MAX_CLOCK) |
<> | 144:ef7eb2e8f9f7 | 288 | { |
<> | 144:ef7eb2e8f9f7 | 289 | dacFreq = DAC_MAX_CLOCK; |
<> | 144:ef7eb2e8f9f7 | 290 | } |
<> | 144:ef7eb2e8f9f7 | 291 | |
<> | 144:ef7eb2e8f9f7 | 292 | /* Use current HFPER frequency? */ |
<> | 144:ef7eb2e8f9f7 | 293 | if (!hfperFreq) |
<> | 144:ef7eb2e8f9f7 | 294 | { |
<> | 144:ef7eb2e8f9f7 | 295 | hfperFreq = CMU_ClockFreqGet(cmuClock_HFPER); |
<> | 144:ef7eb2e8f9f7 | 296 | } |
<> | 144:ef7eb2e8f9f7 | 297 | |
<> | 144:ef7eb2e8f9f7 | 298 | /* Iterate in order to determine best prescale value. Only a few possible */ |
<> | 144:ef7eb2e8f9f7 | 299 | /* values. We start with lowest prescaler value in order to get first */ |
<> | 144:ef7eb2e8f9f7 | 300 | /* equal or below wanted DAC frequency value. */ |
<> | 144:ef7eb2e8f9f7 | 301 | for (ret = 0; ret <= (_DAC_CTRL_PRESC_MASK >> _DAC_CTRL_PRESC_SHIFT); ret++) |
<> | 144:ef7eb2e8f9f7 | 302 | { |
<> | 144:ef7eb2e8f9f7 | 303 | if ((hfperFreq >> ret) <= dacFreq) |
<> | 144:ef7eb2e8f9f7 | 304 | break; |
<> | 144:ef7eb2e8f9f7 | 305 | } |
<> | 144:ef7eb2e8f9f7 | 306 | |
<> | 144:ef7eb2e8f9f7 | 307 | /* If ret is higher than the max prescaler value, make sure to return |
<> | 144:ef7eb2e8f9f7 | 308 | the max value. */ |
<> | 144:ef7eb2e8f9f7 | 309 | if (ret > (_DAC_CTRL_PRESC_MASK >> _DAC_CTRL_PRESC_SHIFT)) |
<> | 144:ef7eb2e8f9f7 | 310 | { |
<> | 144:ef7eb2e8f9f7 | 311 | ret = _DAC_CTRL_PRESC_MASK >> _DAC_CTRL_PRESC_SHIFT; |
<> | 144:ef7eb2e8f9f7 | 312 | } |
<> | 144:ef7eb2e8f9f7 | 313 | |
<> | 144:ef7eb2e8f9f7 | 314 | return (uint8_t)ret; |
<> | 144:ef7eb2e8f9f7 | 315 | } |
<> | 144:ef7eb2e8f9f7 | 316 | |
<> | 144:ef7eb2e8f9f7 | 317 | |
<> | 144:ef7eb2e8f9f7 | 318 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 319 | * @brief |
<> | 144:ef7eb2e8f9f7 | 320 | * Reset DAC to same state as after a HW reset. |
<> | 144:ef7eb2e8f9f7 | 321 | * |
<> | 144:ef7eb2e8f9f7 | 322 | * @param[in] dac |
<> | 144:ef7eb2e8f9f7 | 323 | * Pointer to ADC peripheral register block. |
<> | 144:ef7eb2e8f9f7 | 324 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 325 | void DAC_Reset(DAC_TypeDef *dac) |
<> | 144:ef7eb2e8f9f7 | 326 | { |
<> | 144:ef7eb2e8f9f7 | 327 | /* Disable channels, before resetting other registers. */ |
<> | 144:ef7eb2e8f9f7 | 328 | dac->CH0CTRL = _DAC_CH0CTRL_RESETVALUE; |
<> | 144:ef7eb2e8f9f7 | 329 | dac->CH1CTRL = _DAC_CH1CTRL_RESETVALUE; |
<> | 144:ef7eb2e8f9f7 | 330 | dac->CTRL = _DAC_CTRL_RESETVALUE; |
<> | 144:ef7eb2e8f9f7 | 331 | dac->IEN = _DAC_IEN_RESETVALUE; |
<> | 144:ef7eb2e8f9f7 | 332 | dac->IFC = _DAC_IFC_MASK; |
<> | 144:ef7eb2e8f9f7 | 333 | dac->CAL = DEVINFO->DAC0CAL0; |
<> | 144:ef7eb2e8f9f7 | 334 | dac->BIASPROG = _DAC_BIASPROG_RESETVALUE; |
<> | 144:ef7eb2e8f9f7 | 335 | /* Do not reset route register, setting should be done independently */ |
<> | 144:ef7eb2e8f9f7 | 336 | } |
<> | 144:ef7eb2e8f9f7 | 337 | |
<> | 144:ef7eb2e8f9f7 | 338 | |
<> | 144:ef7eb2e8f9f7 | 339 | /** @} (end addtogroup DAC) */ |
<> | 144:ef7eb2e8f9f7 | 340 | /** @} (end addtogroup EM_Library) */ |
<> | 144:ef7eb2e8f9f7 | 341 | #endif /* defined(DAC_COUNT) && (DAC_COUNT > 0) */ |