Amit Gandhi / sensen_copy_2

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targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/twi_master.h@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
29:d3245924094c
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /* Copyright (c) 2009 Nordic Semiconductor. All Rights Reserved.
bogdanm 0:9b334a45a8ff 2 *
bogdanm 0:9b334a45a8ff 3 * The information contained herein is property of Nordic Semiconductor ASA.
bogdanm 0:9b334a45a8ff 4 * Terms and conditions of usage are described in detail in NORDIC
bogdanm 0:9b334a45a8ff 5 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
bogdanm 0:9b334a45a8ff 6 *
bogdanm 0:9b334a45a8ff 7 * Licensees are granted free, non-transferable use of the information. NO
bogdanm 0:9b334a45a8ff 8 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
bogdanm 0:9b334a45a8ff 9 * the file.
bogdanm 0:9b334a45a8ff 10 *
bogdanm 0:9b334a45a8ff 11 */
bogdanm 0:9b334a45a8ff 12
bogdanm 0:9b334a45a8ff 13 #ifndef TWI_MASTER_H
bogdanm 0:9b334a45a8ff 14 #define TWI_MASTER_H
bogdanm 0:9b334a45a8ff 15
bogdanm 0:9b334a45a8ff 16
bogdanm 0:9b334a45a8ff 17 #ifdef __cplusplus
bogdanm 0:9b334a45a8ff 18 extern "C" {
bogdanm 0:9b334a45a8ff 19 #endif
bogdanm 0:9b334a45a8ff 20
bogdanm 0:9b334a45a8ff 21 /*lint ++flb "Enter library region" */
bogdanm 0:9b334a45a8ff 22
bogdanm 0:9b334a45a8ff 23 #include <stdbool.h>
bogdanm 0:9b334a45a8ff 24 #include <stdint.h>
bogdanm 0:9b334a45a8ff 25
bogdanm 0:9b334a45a8ff 26 /** @file
bogdanm 0:9b334a45a8ff 27 * @brief Software controlled TWI Master driver.
bogdanm 0:9b334a45a8ff 28 *
bogdanm 0:9b334a45a8ff 29 *
bogdanm 0:9b334a45a8ff 30 * @defgroup lib_driver_twi_master Software controlled TWI Master driver
bogdanm 0:9b334a45a8ff 31 * @{
bogdanm 0:9b334a45a8ff 32 * @ingroup nrf_drivers
bogdanm 0:9b334a45a8ff 33 * @brief Software controlled TWI Master driver.
bogdanm 0:9b334a45a8ff 34 *
bogdanm 0:9b334a45a8ff 35 * Supported features:
bogdanm 0:9b334a45a8ff 36 * - Repeated start
bogdanm 0:9b334a45a8ff 37 * - No multi-master
bogdanm 0:9b334a45a8ff 38 * - Only 7-bit addressing
bogdanm 0:9b334a45a8ff 39 * - Supports clock stretching (with optional SMBus style slave timeout)
bogdanm 0:9b334a45a8ff 40 * - Tries to handle slaves stuck in the middle of transfer
bogdanm 0:9b334a45a8ff 41 */
bogdanm 0:9b334a45a8ff 42
bogdanm 0:9b334a45a8ff 43 #define TWI_READ_BIT (0x01) //!< If this bit is set in the address field, transfer direction is from slave to master.
bogdanm 0:9b334a45a8ff 44
bogdanm 0:9b334a45a8ff 45 #define TWI_ISSUE_STOP ((bool)true) //!< Parameter for @ref twi_master_transfer
bogdanm 0:9b334a45a8ff 46 #define TWI_DONT_ISSUE_STOP ((bool)false) //!< Parameter for @ref twi_master_transfer
bogdanm 0:9b334a45a8ff 47
bogdanm 0:9b334a45a8ff 48 /* These macros are needed to see if the slave is stuck and we as master send dummy clock cycles to end its wait */
bogdanm 0:9b334a45a8ff 49 /*lint -e717 -save "Suppress do {} while (0) for these macros" */
bogdanm 0:9b334a45a8ff 50 /*lint ++flb "Enter library region" */
bogdanm 0:9b334a45a8ff 51 #define TWI_SCL_HIGH() do { NRF_GPIO->OUTSET = (1UL << TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER); } while(0) /*!< Pulls SCL line high */
bogdanm 0:9b334a45a8ff 52 #define TWI_SCL_LOW() do { NRF_GPIO->OUTCLR = (1UL << TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER); } while(0) /*!< Pulls SCL line low */
bogdanm 0:9b334a45a8ff 53 #define TWI_SDA_HIGH() do { NRF_GPIO->OUTSET = (1UL << TWI_MASTER_CONFIG_DATA_PIN_NUMBER); } while(0) /*!< Pulls SDA line high */
bogdanm 0:9b334a45a8ff 54 #define TWI_SDA_LOW() do { NRF_GPIO->OUTCLR = (1UL << TWI_MASTER_CONFIG_DATA_PIN_NUMBER); } while(0) /*!< Pulls SDA line low */
bogdanm 0:9b334a45a8ff 55 #define TWI_SDA_INPUT() do { NRF_GPIO->DIRCLR = (1UL << TWI_MASTER_CONFIG_DATA_PIN_NUMBER); } while(0) /*!< Configures SDA pin as input */
bogdanm 0:9b334a45a8ff 56 #define TWI_SDA_OUTPUT() do { NRF_GPIO->DIRSET = (1UL << TWI_MASTER_CONFIG_DATA_PIN_NUMBER); } while(0) /*!< Configures SDA pin as output */
bogdanm 0:9b334a45a8ff 57 #define TWI_SCL_OUTPUT() do { NRF_GPIO->DIRSET = (1UL << TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER); } while(0) /*!< Configures SCL pin as output */
bogdanm 0:9b334a45a8ff 58 /*lint -restore */
bogdanm 0:9b334a45a8ff 59
bogdanm 0:9b334a45a8ff 60 #define TWI_SDA_READ() ((NRF_GPIO->IN >> TWI_MASTER_CONFIG_DATA_PIN_NUMBER) & 0x1UL) /*!< Reads current state of SDA */
bogdanm 0:9b334a45a8ff 61 #define TWI_SCL_READ() ((NRF_GPIO->IN >> TWI_MASTER_CONFIG_CLOCK_PIN_NUMBER) & 0x1UL) /*!< Reads current state of SCL */
bogdanm 0:9b334a45a8ff 62
bogdanm 0:9b334a45a8ff 63 #define TWI_DELAY() nrf_delay_us(4) /*!< Time to wait when pin states are changed. For fast-mode the delay can be zero and for standard-mode 4 us delay is sufficient. */
bogdanm 0:9b334a45a8ff 64
bogdanm 0:9b334a45a8ff 65
bogdanm 0:9b334a45a8ff 66 /**
bogdanm 0:9b334a45a8ff 67 * @brief Function for initializing TWI bus IO pins and checks if the bus is operational.
bogdanm 0:9b334a45a8ff 68 *
bogdanm 0:9b334a45a8ff 69 * Both pins are configured as Standard-0, No-drive-1 (open drain).
bogdanm 0:9b334a45a8ff 70 *
bogdanm 0:9b334a45a8ff 71 * @return
bogdanm 0:9b334a45a8ff 72 * @retval true TWI bus is clear for transfers.
bogdanm 0:9b334a45a8ff 73 * @retval false TWI bus is stuck.
bogdanm 0:9b334a45a8ff 74 */
bogdanm 0:9b334a45a8ff 75 bool twi_master_init_and_clear(void);
bogdanm 0:9b334a45a8ff 76
bogdanm 0:9b334a45a8ff 77 /**
bogdanm 0:9b334a45a8ff 78 * @brief Function for transferring data over TWI bus.
bogdanm 0:9b334a45a8ff 79 *
bogdanm 0:9b334a45a8ff 80 * If TWI master detects even one NACK from the slave or timeout occurs, STOP condition is issued
bogdanm 0:9b334a45a8ff 81 * and the function returns false.
bogdanm 0:9b334a45a8ff 82 * Bit 0 (@ref TWI_READ_BIT) in the address parameter controls transfer direction;
bogdanm 0:9b334a45a8ff 83 * - If 1, master reads data_length number of bytes from the slave
bogdanm 0:9b334a45a8ff 84 * - If 0, master writes data_length number of bytes to the slave.
bogdanm 0:9b334a45a8ff 85 *
bogdanm 0:9b334a45a8ff 86 * @note Make sure at least data_length number of bytes is allocated in data if TWI_READ_BIT is set.
bogdanm 0:9b334a45a8ff 87 * @note @ref TWI_ISSUE_STOP
bogdanm 0:9b334a45a8ff 88 *
bogdanm 0:9b334a45a8ff 89 * @param address Data transfer direction (LSB) / Slave address (7 MSBs).
bogdanm 0:9b334a45a8ff 90 * @param data Pointer to data.
bogdanm 0:9b334a45a8ff 91 * @param data_length Number of bytes to transfer.
bogdanm 0:9b334a45a8ff 92 * @param issue_stop_condition If @ref TWI_ISSUE_STOP, STOP condition is issued before exiting function. If @ref TWI_DONT_ISSUE_STOP, STOP condition is not issued before exiting function. If transfer failed for any reason, STOP condition will be issued in any case.
bogdanm 0:9b334a45a8ff 93 * @return
bogdanm 0:9b334a45a8ff 94 * @retval true Data transfer succeeded without errors.
bogdanm 0:9b334a45a8ff 95 * @retval false Data transfer failed.
bogdanm 0:9b334a45a8ff 96 */
bogdanm 0:9b334a45a8ff 97 bool twi_master_transfer(uint8_t address, uint8_t *data, uint8_t data_length, bool issue_stop_condition);
bogdanm 0:9b334a45a8ff 98
bogdanm 0:9b334a45a8ff 99 /**
bogdanm 0:9b334a45a8ff 100 *@}
bogdanm 0:9b334a45a8ff 101 **/
bogdanm 0:9b334a45a8ff 102
bogdanm 0:9b334a45a8ff 103 #ifdef __cplusplus
bogdanm 0:9b334a45a8ff 104 }
bogdanm 0:9b334a45a8ff 105 #endif
bogdanm 0:9b334a45a8ff 106
bogdanm 0:9b334a45a8ff 107 /*lint --flb "Leave library region" */
bogdanm 0:9b334a45a8ff 108 #endif //TWI_MASTER_H