Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Freescale/TARGET_KSDK2_MCUS/TARGET_K66F/drivers/fsl_crc.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?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /*
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2015, Freescale Semiconductor, Inc.
<> 144:ef7eb2e8f9f7 3 * All rights reserved.
<> 144:ef7eb2e8f9f7 4 *
<> 144:ef7eb2e8f9f7 5 * Redistribution and use in source and binary forms, with or without modification,
<> 144:ef7eb2e8f9f7 6 * are permitted provided that the following conditions are met:
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * o Redistributions of source code must retain the above copyright notice, this list
<> 144:ef7eb2e8f9f7 9 * of conditions and the following disclaimer.
<> 144:ef7eb2e8f9f7 10 *
<> 144:ef7eb2e8f9f7 11 * o Redistributions in binary form must reproduce the above copyright notice, this
<> 144:ef7eb2e8f9f7 12 * list of conditions and the following disclaimer in the documentation and/or
<> 144:ef7eb2e8f9f7 13 * other materials provided with the distribution.
<> 144:ef7eb2e8f9f7 14 *
<> 144:ef7eb2e8f9f7 15 * o Neither the name of Freescale Semiconductor, Inc. nor the names of its
<> 144:ef7eb2e8f9f7 16 * contributors may be used to endorse or promote products derived from this
<> 144:ef7eb2e8f9f7 17 * software without specific prior written permission.
<> 144:ef7eb2e8f9f7 18 *
<> 144:ef7eb2e8f9f7 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
<> 144:ef7eb2e8f9f7 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
<> 144:ef7eb2e8f9f7 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
<> 144:ef7eb2e8f9f7 22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
<> 144:ef7eb2e8f9f7 23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
<> 144:ef7eb2e8f9f7 24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
<> 144:ef7eb2e8f9f7 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
<> 144:ef7eb2e8f9f7 26 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
<> 144:ef7eb2e8f9f7 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
<> 144:ef7eb2e8f9f7 28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
<> 144:ef7eb2e8f9f7 29 */
<> 144:ef7eb2e8f9f7 30 #include "fsl_crc.h"
<> 144:ef7eb2e8f9f7 31
<> 144:ef7eb2e8f9f7 32 /*******************************************************************************
<> 144:ef7eb2e8f9f7 33 * Definitions
<> 144:ef7eb2e8f9f7 34 ******************************************************************************/
<> 144:ef7eb2e8f9f7 35
<> 144:ef7eb2e8f9f7 36 #if defined(CRC_DRIVER_USE_CRC16_CCIT_FALSE_AS_DEFAULT) && CRC_DRIVER_USE_CRC16_CCIT_FALSE_AS_DEFAULT
<> 144:ef7eb2e8f9f7 37 /* @brief Default user configuration structure for CRC-16-CCITT */
<> 144:ef7eb2e8f9f7 38 #define CRC_DRIVER_DEFAULT_POLYNOMIAL 0x1021U
<> 144:ef7eb2e8f9f7 39 /*< CRC-16-CCIT polynomial x**16 + x**12 + x**5 + x**0 */
<> 144:ef7eb2e8f9f7 40 #define CRC_DRIVER_DEFAULT_SEED 0xFFFFU
<> 144:ef7eb2e8f9f7 41 /*< Default initial checksum */
<> 144:ef7eb2e8f9f7 42 #define CRC_DRIVER_DEFAULT_REFLECT_IN false
<> 144:ef7eb2e8f9f7 43 /*< Default is no transpose */
<> 144:ef7eb2e8f9f7 44 #define CRC_DRIVER_DEFAULT_REFLECT_OUT false
<> 144:ef7eb2e8f9f7 45 /*< Default is transpose bytes */
<> 144:ef7eb2e8f9f7 46 #define CRC_DRIVER_DEFAULT_COMPLEMENT_CHECKSUM false
<> 144:ef7eb2e8f9f7 47 /*< Default is without complement of CRC data register read data */
<> 144:ef7eb2e8f9f7 48 #define CRC_DRIVER_DEFAULT_CRC_BITS kCrcBits16
<> 144:ef7eb2e8f9f7 49 /*< Default is 16-bit CRC protocol */
<> 144:ef7eb2e8f9f7 50 #define CRC_DRIVER_DEFAULT_CRC_RESULT kCrcFinalChecksum
<> 144:ef7eb2e8f9f7 51 /*< Default is resutl type is final checksum */
<> 144:ef7eb2e8f9f7 52 #endif /* CRC_DRIVER_USE_CRC16_CCIT_FALSE_AS_DEFAULT */
<> 144:ef7eb2e8f9f7 53
<> 144:ef7eb2e8f9f7 54 /*! @brief CRC type of transpose of read write data */
<> 144:ef7eb2e8f9f7 55 typedef enum _crc_transpose_type
<> 144:ef7eb2e8f9f7 56 {
<> 144:ef7eb2e8f9f7 57 kCrcTransposeNone = 0U, /*! No transpose */
<> 144:ef7eb2e8f9f7 58 kCrcTransposeBits = 1U, /*! Tranpose bits in bytes */
<> 144:ef7eb2e8f9f7 59 kCrcTransposeBitsAndBytes = 2U, /*! Transpose bytes and bits in bytes */
<> 144:ef7eb2e8f9f7 60 kCrcTransposeBytes = 3U, /*! Transpose bytes */
<> 144:ef7eb2e8f9f7 61 } crc_transpose_type_t;
<> 144:ef7eb2e8f9f7 62
<> 144:ef7eb2e8f9f7 63 /*!
<> 144:ef7eb2e8f9f7 64 * @brief CRC module configuration.
<> 144:ef7eb2e8f9f7 65 *
<> 144:ef7eb2e8f9f7 66 * This structure holds the configuration for the CRC module.
<> 144:ef7eb2e8f9f7 67 */
<> 144:ef7eb2e8f9f7 68 typedef struct _crc_module_config
<> 144:ef7eb2e8f9f7 69 {
<> 144:ef7eb2e8f9f7 70 uint32_t polynomial; /*!< CRC Polynomial, MSBit first.@n
<> 144:ef7eb2e8f9f7 71 Example polynomial: 0x1021 = 1_0000_0010_0001 = x^12+x^5+1 */
<> 144:ef7eb2e8f9f7 72 uint32_t seed; /*!< Starting checksum value */
<> 144:ef7eb2e8f9f7 73 crc_transpose_type_t readTranspose; /*!< Type of transpose when reading CRC result. */
<> 144:ef7eb2e8f9f7 74 crc_transpose_type_t writeTranspose; /*!< Type of transpose when writing CRC input data. */
<> 144:ef7eb2e8f9f7 75 bool complementChecksum; /*!< True if the result shall be complement of the actual checksum. */
<> 144:ef7eb2e8f9f7 76 crc_bits_t crcBits; /*!< Selects 16- or 32- bit CRC protocol. */
<> 144:ef7eb2e8f9f7 77 } crc_module_config_t;
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 /*******************************************************************************
<> 144:ef7eb2e8f9f7 80 * Code
<> 144:ef7eb2e8f9f7 81 ******************************************************************************/
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 /*!
<> 144:ef7eb2e8f9f7 84 * @brief Returns transpose type for CRC protocol reflect in parameter.
<> 144:ef7eb2e8f9f7 85 *
<> 144:ef7eb2e8f9f7 86 * This functions helps to set writeTranspose member of crc_config_t structure. Reflect in is CRC protocol parameter.
<> 144:ef7eb2e8f9f7 87 *
<> 144:ef7eb2e8f9f7 88 * @param enable True or false for the selected CRC protocol Reflect In (refin) parameter.
<> 144:ef7eb2e8f9f7 89 */
<> 144:ef7eb2e8f9f7 90 static inline crc_transpose_type_t crc_GetTransposeTypeFromReflectIn(bool enable)
<> 144:ef7eb2e8f9f7 91 {
<> 144:ef7eb2e8f9f7 92 return ((enable) ? kCrcTransposeBitsAndBytes : kCrcTransposeBytes);
<> 144:ef7eb2e8f9f7 93 }
<> 144:ef7eb2e8f9f7 94
<> 144:ef7eb2e8f9f7 95 /*!
<> 144:ef7eb2e8f9f7 96 * @brief Returns transpose type for CRC protocol reflect out parameter.
<> 144:ef7eb2e8f9f7 97 *
<> 144:ef7eb2e8f9f7 98 * This functions helps to set readTranspose member of crc_config_t structure. Reflect out is CRC protocol parameter.
<> 144:ef7eb2e8f9f7 99 *
<> 144:ef7eb2e8f9f7 100 * @param enable True or false for the selected CRC protocol Reflect Out (refout) parameter.
<> 144:ef7eb2e8f9f7 101 */
<> 144:ef7eb2e8f9f7 102 static inline crc_transpose_type_t crc_GetTransposeTypeFromReflectOut(bool enable)
<> 144:ef7eb2e8f9f7 103 {
<> 144:ef7eb2e8f9f7 104 return ((enable) ? kCrcTransposeBitsAndBytes : kCrcTransposeNone);
<> 144:ef7eb2e8f9f7 105 }
<> 144:ef7eb2e8f9f7 106
<> 144:ef7eb2e8f9f7 107 /*!
<> 144:ef7eb2e8f9f7 108 * @brief Starts checksum computation.
<> 144:ef7eb2e8f9f7 109 *
<> 144:ef7eb2e8f9f7 110 * Configures the CRC module for the specified CRC protocol. @n
<> 144:ef7eb2e8f9f7 111 * Starts the checksum computation by writing the seed value
<> 144:ef7eb2e8f9f7 112 *
<> 144:ef7eb2e8f9f7 113 * @param base CRC peripheral address.
<> 144:ef7eb2e8f9f7 114 * @param config Pointer to protocol configuration structure.
<> 144:ef7eb2e8f9f7 115 */
<> 144:ef7eb2e8f9f7 116 static void crc_ConfigureAndStart(CRC_Type *base, const crc_module_config_t *config)
<> 144:ef7eb2e8f9f7 117 {
<> 144:ef7eb2e8f9f7 118 uint32_t crcControl;
<> 144:ef7eb2e8f9f7 119
<> 144:ef7eb2e8f9f7 120 /* pre-compute value for CRC control registger based on user configuraton without WAS field */
<> 144:ef7eb2e8f9f7 121 crcControl = 0 | CRC_CTRL_TOT(config->writeTranspose) | CRC_CTRL_TOTR(config->readTranspose) |
<> 144:ef7eb2e8f9f7 122 CRC_CTRL_FXOR(config->complementChecksum) | CRC_CTRL_TCRC(config->crcBits);
<> 144:ef7eb2e8f9f7 123
<> 144:ef7eb2e8f9f7 124 /* make sure the control register is clear - WAS is deasserted, and protocol is set */
<> 144:ef7eb2e8f9f7 125 base->CTRL = crcControl;
<> 144:ef7eb2e8f9f7 126
<> 144:ef7eb2e8f9f7 127 /* write polynomial register */
<> 144:ef7eb2e8f9f7 128 base->GPOLY = config->polynomial;
<> 144:ef7eb2e8f9f7 129
<> 144:ef7eb2e8f9f7 130 /* write pre-computed control register value along with WAS to start checksum computation */
<> 144:ef7eb2e8f9f7 131 base->CTRL = crcControl | CRC_CTRL_WAS(true);
<> 144:ef7eb2e8f9f7 132
<> 144:ef7eb2e8f9f7 133 /* write seed (initial checksum) */
<> 144:ef7eb2e8f9f7 134 base->DATA = config->seed;
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 /* deassert WAS by writing pre-computed CRC control register value */
<> 144:ef7eb2e8f9f7 137 base->CTRL = crcControl;
<> 144:ef7eb2e8f9f7 138 }
<> 144:ef7eb2e8f9f7 139
<> 144:ef7eb2e8f9f7 140 /*!
<> 144:ef7eb2e8f9f7 141 * @brief Starts final checksum computation.
<> 144:ef7eb2e8f9f7 142 *
<> 144:ef7eb2e8f9f7 143 * Configures the CRC module for the specified CRC protocol. @n
<> 144:ef7eb2e8f9f7 144 * Starts final checksum computation by writing the seed value.
<> 144:ef7eb2e8f9f7 145 * @note CRC_Get16bitResult() or CRC_Get32bitResult() return final checksum
<> 144:ef7eb2e8f9f7 146 * (output reflection and xor functions are applied).
<> 144:ef7eb2e8f9f7 147 *
<> 144:ef7eb2e8f9f7 148 * @param base CRC peripheral address.
<> 144:ef7eb2e8f9f7 149 * @param protocolConfig Pointer to protocol configuration structure.
<> 144:ef7eb2e8f9f7 150 */
<> 144:ef7eb2e8f9f7 151 static void crc_SetProtocolConfig(CRC_Type *base, const crc_config_t *protocolConfig)
<> 144:ef7eb2e8f9f7 152 {
<> 144:ef7eb2e8f9f7 153 crc_module_config_t moduleConfig;
<> 144:ef7eb2e8f9f7 154 /* convert protocol to CRC peripheral module configuration, prepare for final checksum */
<> 144:ef7eb2e8f9f7 155 moduleConfig.polynomial = protocolConfig->polynomial;
<> 144:ef7eb2e8f9f7 156 moduleConfig.seed = protocolConfig->seed;
<> 144:ef7eb2e8f9f7 157 moduleConfig.readTranspose = crc_GetTransposeTypeFromReflectOut(protocolConfig->reflectOut);
<> 144:ef7eb2e8f9f7 158 moduleConfig.writeTranspose = crc_GetTransposeTypeFromReflectIn(protocolConfig->reflectIn);
<> 144:ef7eb2e8f9f7 159 moduleConfig.complementChecksum = protocolConfig->complementChecksum;
<> 144:ef7eb2e8f9f7 160 moduleConfig.crcBits = protocolConfig->crcBits;
<> 144:ef7eb2e8f9f7 161
<> 144:ef7eb2e8f9f7 162 crc_ConfigureAndStart(base, &moduleConfig);
<> 144:ef7eb2e8f9f7 163 }
<> 144:ef7eb2e8f9f7 164
<> 144:ef7eb2e8f9f7 165 /*!
<> 144:ef7eb2e8f9f7 166 * @brief Starts intermediate checksum computation.
<> 144:ef7eb2e8f9f7 167 *
<> 144:ef7eb2e8f9f7 168 * Configures the CRC module for the specified CRC protocol. @n
<> 144:ef7eb2e8f9f7 169 * Starts intermediate checksum computation by writing the seed value.
<> 144:ef7eb2e8f9f7 170 * @note CRC_Get16bitResult() or CRC_Get32bitResult() return intermediate checksum (raw data register value).
<> 144:ef7eb2e8f9f7 171 *
<> 144:ef7eb2e8f9f7 172 * @param base CRC peripheral address.
<> 144:ef7eb2e8f9f7 173 * @param protocolConfig Pointer to protocol configuration structure.
<> 144:ef7eb2e8f9f7 174 */
<> 144:ef7eb2e8f9f7 175 static void crc_SetRawProtocolConfig(CRC_Type *base, const crc_config_t *protocolConfig)
<> 144:ef7eb2e8f9f7 176 {
<> 144:ef7eb2e8f9f7 177 crc_module_config_t moduleConfig;
<> 144:ef7eb2e8f9f7 178 /* convert protocol to CRC peripheral module configuration, prepare for intermediate checksum */
<> 144:ef7eb2e8f9f7 179 moduleConfig.polynomial = protocolConfig->polynomial;
<> 144:ef7eb2e8f9f7 180 moduleConfig.seed = protocolConfig->seed;
<> 144:ef7eb2e8f9f7 181 moduleConfig.readTranspose =
<> 144:ef7eb2e8f9f7 182 kCrcTransposeNone; /* intermediate checksum does no transpose of data register read value */
<> 144:ef7eb2e8f9f7 183 moduleConfig.writeTranspose = crc_GetTransposeTypeFromReflectIn(protocolConfig->reflectIn);
<> 144:ef7eb2e8f9f7 184 moduleConfig.complementChecksum = false; /* intermediate checksum does no xor of data register read value */
<> 144:ef7eb2e8f9f7 185 moduleConfig.crcBits = protocolConfig->crcBits;
<> 144:ef7eb2e8f9f7 186
<> 144:ef7eb2e8f9f7 187 crc_ConfigureAndStart(base, &moduleConfig);
<> 144:ef7eb2e8f9f7 188 }
<> 144:ef7eb2e8f9f7 189
<> 144:ef7eb2e8f9f7 190 void CRC_Init(CRC_Type *base, const crc_config_t *config)
<> 144:ef7eb2e8f9f7 191 {
<> 144:ef7eb2e8f9f7 192 /* ungate clock */
<> 144:ef7eb2e8f9f7 193 CLOCK_EnableClock(kCLOCK_Crc0);
<> 144:ef7eb2e8f9f7 194 /* configure CRC module and write the seed */
<> 144:ef7eb2e8f9f7 195 if (config->crcResult == kCrcFinalChecksum)
<> 144:ef7eb2e8f9f7 196 {
<> 144:ef7eb2e8f9f7 197 crc_SetProtocolConfig(base, config);
<> 144:ef7eb2e8f9f7 198 }
<> 144:ef7eb2e8f9f7 199 else
<> 144:ef7eb2e8f9f7 200 {
<> 144:ef7eb2e8f9f7 201 crc_SetRawProtocolConfig(base, config);
<> 144:ef7eb2e8f9f7 202 }
<> 144:ef7eb2e8f9f7 203 }
<> 144:ef7eb2e8f9f7 204
<> 144:ef7eb2e8f9f7 205 void CRC_GetDefaultConfig(crc_config_t *config)
<> 144:ef7eb2e8f9f7 206 {
<> 144:ef7eb2e8f9f7 207 static const crc_config_t crc16ccit = {
<> 144:ef7eb2e8f9f7 208 CRC_DRIVER_DEFAULT_POLYNOMIAL, CRC_DRIVER_DEFAULT_SEED,
<> 144:ef7eb2e8f9f7 209 CRC_DRIVER_DEFAULT_REFLECT_IN, CRC_DRIVER_DEFAULT_REFLECT_OUT,
<> 144:ef7eb2e8f9f7 210 CRC_DRIVER_DEFAULT_COMPLEMENT_CHECKSUM, CRC_DRIVER_DEFAULT_CRC_BITS,
<> 144:ef7eb2e8f9f7 211 CRC_DRIVER_DEFAULT_CRC_RESULT,
<> 144:ef7eb2e8f9f7 212 };
<> 144:ef7eb2e8f9f7 213
<> 144:ef7eb2e8f9f7 214 *config = crc16ccit;
<> 144:ef7eb2e8f9f7 215 }
<> 144:ef7eb2e8f9f7 216
<> 144:ef7eb2e8f9f7 217 void CRC_WriteData(CRC_Type *base, const uint8_t *data, size_t dataSize)
<> 144:ef7eb2e8f9f7 218 {
<> 144:ef7eb2e8f9f7 219 const uint32_t *data32;
<> 144:ef7eb2e8f9f7 220
<> 144:ef7eb2e8f9f7 221 /* 8-bit reads and writes till source address is aligned 4 bytes */
<> 144:ef7eb2e8f9f7 222 while ((dataSize) && ((uint32_t)data & 3U))
<> 144:ef7eb2e8f9f7 223 {
<> 144:ef7eb2e8f9f7 224 base->ACCESS8BIT.DATALL = *data;
<> 144:ef7eb2e8f9f7 225 data++;
<> 144:ef7eb2e8f9f7 226 dataSize--;
<> 144:ef7eb2e8f9f7 227 }
<> 144:ef7eb2e8f9f7 228
<> 144:ef7eb2e8f9f7 229 /* use 32-bit reads and writes as long as possible */
<> 144:ef7eb2e8f9f7 230 data32 = (const uint32_t *)data;
<> 144:ef7eb2e8f9f7 231 while (dataSize >= sizeof(uint32_t))
<> 144:ef7eb2e8f9f7 232 {
<> 144:ef7eb2e8f9f7 233 base->DATA = *data32;
<> 144:ef7eb2e8f9f7 234 data32++;
<> 144:ef7eb2e8f9f7 235 dataSize -= sizeof(uint32_t);
<> 144:ef7eb2e8f9f7 236 }
<> 144:ef7eb2e8f9f7 237
<> 144:ef7eb2e8f9f7 238 data = (const uint8_t *)data32;
<> 144:ef7eb2e8f9f7 239
<> 144:ef7eb2e8f9f7 240 /* 8-bit reads and writes till end of data buffer */
<> 144:ef7eb2e8f9f7 241 while (dataSize)
<> 144:ef7eb2e8f9f7 242 {
<> 144:ef7eb2e8f9f7 243 base->ACCESS8BIT.DATALL = *data;
<> 144:ef7eb2e8f9f7 244 data++;
<> 144:ef7eb2e8f9f7 245 dataSize--;
<> 144:ef7eb2e8f9f7 246 }
<> 144:ef7eb2e8f9f7 247 }
<> 144:ef7eb2e8f9f7 248
<> 144:ef7eb2e8f9f7 249 uint16_t CRC_Get16bitResult(CRC_Type *base)
<> 144:ef7eb2e8f9f7 250 {
<> 144:ef7eb2e8f9f7 251 uint32_t retval;
<> 144:ef7eb2e8f9f7 252 uint32_t totr; /* type of transpose read bitfield */
<> 144:ef7eb2e8f9f7 253
<> 144:ef7eb2e8f9f7 254 retval = base->DATA;
<> 144:ef7eb2e8f9f7 255 totr = (base->CTRL & CRC_CTRL_TOTR_MASK) >> CRC_CTRL_TOTR_SHIFT;
<> 144:ef7eb2e8f9f7 256
<> 144:ef7eb2e8f9f7 257 /* check transpose type to get 16-bit out of 32-bit register */
<> 144:ef7eb2e8f9f7 258 if (totr >= 2U)
<> 144:ef7eb2e8f9f7 259 {
<> 144:ef7eb2e8f9f7 260 /* transpose of bytes for read is set, the result CRC is in CRC_DATA[HU:HL] */
<> 144:ef7eb2e8f9f7 261 retval &= 0xFFFF0000U;
<> 144:ef7eb2e8f9f7 262 retval = retval >> 16U;
<> 144:ef7eb2e8f9f7 263 }
<> 144:ef7eb2e8f9f7 264 else
<> 144:ef7eb2e8f9f7 265 {
<> 144:ef7eb2e8f9f7 266 /* no transpose of bytes for read, the result CRC is in CRC_DATA[LU:LL] */
<> 144:ef7eb2e8f9f7 267 retval &= 0x0000FFFFU;
<> 144:ef7eb2e8f9f7 268 }
<> 144:ef7eb2e8f9f7 269 return (uint16_t)retval;
<> 144:ef7eb2e8f9f7 270 }