mxm_bitextract.c

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/**
 * @file    mxm_bitextract.c
 * @author  foxBMS Team
 * @date    2019-01-15 (date of creation)
 * @updated 2021-12-06 (date of last update)
 * @ingroup DRIVERS
 * @prefix  MXM
 *
 * @brief   Bit extraction function for mxm_17841b
 *
 * @details This module supplies a specific bit extraction functionality to
 *          read & write into status registers. The different statuses that are
 *          read from or write into are indicated in the enum.
 *          Battery monitoring driver for MAX1785x battery monitoring ICs.
 *
 */
 
/*========== Includes =======================================================*/
#include "mxm_bitextract.h"
 
/*========== Macros and Definitions =========================================*/
 
/*========== Static Constant and Variable Definitions =======================*/
 
/*========== Extern Constant and Variable Definitions =======================*/
 
/*========== Static Function Prototypes =====================================*/
/**
 * @brief       Extract a bit value function
 * @details     The function is used to extract some number of bits (numOfBits)
 *              from a position (pos) to write or read from the configuration
 *              and status registers.
 * @param[in]   value           value of the bits that shall be written or read
 * @param[in]   numberOfBits    number of bits to be extracted from the value
 *                              register
 * @param[in]   position        position of bits to be extracted from the value
 *                              register, start from right to left
 * @param[in]   shift           number of bit-shift to the left for read
 *                              function the shift value is zero.
 * @return      bit values for registers
 */
static MXM_41B_REG_BIT_VALUE bitValue(
    MXM_41B_REG_BIT_VALUE value,
    uint8_t numberOfBits,
    MXM_41B_REG_BITS position,
    MXM_41B_REG_BITS shift);
 
/*========== Static Function Implementations ================================*/
static MXM_41B_REG_BIT_VALUE bitValue(
    MXM_41B_REG_BIT_VALUE value,
    uint8_t numberOfBits,
    MXM_41B_REG_BITS position,
    MXM_41B_REG_BITS shift) {
    MXM_41B_REG_BIT_VALUE sBit;
    sBit = (((1u << numberOfBits) - 1u) & (((uint8_t)value) >> (position - 1u)));
    return (MXM_41B_REG_BIT_VALUE)((((uint8_t)sBit) << shift) & (uint8_t)UINT8_MAX);
}
 
/*========== Extern Function Implementations ================================*/
extern MXM_41B_REG_BIT_VALUE mxm_41bReadValue(uint8_t reg, uint8_t numberOfBits, MXM_41B_REG_BITS position) {
    return bitValue(reg, numberOfBits, (position + 1u), 0);
}
 
extern MXM_41B_REG_BIT_VALUE mxm_41bWriteValue(
    MXM_41B_REG_BIT_VALUE value,
    uint8_t numberOfBits,
    MXM_41B_REG_BITS shift,
    uint8_t reg) {
    uint8_t outputRegister = reg;
    outputRegister         = outputRegister & ~(MXM_REG_MASK(shift, numberOfBits));
    outputRegister         = bitValue(value, numberOfBits, 1, shift) | outputRegister;
    return outputRegister;
}
 
/*========== Externalized Static Function Implementations (Unit Test) =======*/