26.3.3.8 i2c_m_sync_cmd_read

Sync version of read register value from I2C slave.

int32_t i2c_m_sync_cmd_read(
    struct i2c_m_sync_desc * i2c,
    uint8_t reg,
    uint8_t * buffer,
    uint8_t length
)

This function will read a byte value from a specified register in the I2C slave device and then wait for this operation to be done.

The sequence of this routine is sta->address(write)->ack->reg address->ack->resta->address(read)->ack->reg value->nack->stt

Parameters

i2c

Type: struct i2c_m_sync_desc Struct *

An I2C descriptor, which is used to communicate through I2C

reg

Type: uint8_t

The internal address/register of the I2C slave device

buffer

Type: uint8_t *

The buffer to hold the read data from the I2C slave device

length

Type: uint8_t

The length (in bytes) to read from the I2C slave device

Type: int32_t

Whether successfully read from the device