What is OTP bank in the code to read mpu9150 using dmp?

Other Hardware Sensors
1

I am using arduino mega 2560 to read data from mpu9150 through dmp. When I read the code, I don't understand what OTP bank is although I spent a lot of time searching for it. Can anyone know what it is? In addition, the register MPU9150_RA_XG_OFFS_TC address is 0x00, which is not mentioned in mpu9150 datasheet.

// ======== UNDOCUMENTED/DMP REGISTERS/METHODS ========

// XG_OFFS_TC register

uint8_t MPU9150::getOTPBankValid() {
    I2Cdev::readBit(devAddr, MPU9150_RA_XG_OFFS_TC, MPU9150_TC_OTP_BNK_VLD_BIT, buffer);
    return buffer[0];
}
void MPU9150::setOTPBankValid(bool enabled) {
    I2Cdev::writeBit(devAddr, MPU9150_RA_XG_OFFS_TC, MPU9150_TC_OTP_BNK_VLD_BIT, enabled);
}
int8_t MPU9150::getXGyroOffsetTC() {
    I2Cdev::readBits(devAddr, MPU9150_RA_XG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, buffer);
    return buffer[0];
}
void MPU9150::setXGyroOffsetTC(int8_t offset) {
    I2Cdev::writeBits(devAddr, MPU9150_RA_XG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, offset);
}

// YG_OFFS_TC register

int8_t MPU9150::getYGyroOffsetTC() {
    I2Cdev::readBits(devAddr, MPU9150_RA_YG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, buffer);
    return buffer[0];
}
void MPU9150::setYGyroOffsetTC(int8_t offset) {
    I2Cdev::writeBits(devAddr, MPU9150_RA_YG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, offset);
}

// ZG_OFFS_TC register

int8_t MPU9150::getZGyroOffsetTC() {
    I2Cdev::readBits(devAddr, MPU9150_RA_ZG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, buffer);
    return buffer[0];
}
void MPU9150::setZGyroOffsetTC(int8_t offset) {
    I2Cdev::writeBits(devAddr, MPU9150_RA_ZG_OFFS_TC, MPU9150_TC_OFFSET_BIT, MPU9150_TC_OFFSET_LENGTH, offset);
}

#define MPU9150_RA_XG_OFFS_TC       0x00 //[7] PWR_MODE, [6:1] XG_OFFS_TC, [0] OTP_BNK_VLD
#define MPU9150_RA_YG_OFFS_TC       0x01 //[7] PWR_MODE, [6:1] YG_OFFS_TC, [0] OTP_BNK_VLD
#define MPU9150_RA_ZG_OFFS_TC       0x02 //[7] PWR_MODE, [6:1] ZG_OFFS_TC, [0] OTP_BNK_VLD

#define MPU9150_TC_PWR_MODE_BIT     7
#define MPU9150_TC_OFFSET_BIT       6
#define MPU9150_TC_OFFSET_LENGTH    6
#define MPU9150_TC_OTP_BNK_VLD_BIT  0
2

OTP = One Time Programmable, usually a small memory where the mfg writes serial numbers and such.

3

I have 1 more question, in MPU9250 register map, register at address 0x00 is gyro seft-test. But in MPU9150, register 0x00 is not mentioned in its register map. Are they corresponeding?