MAX127_CTRL_RNG
scale = (ctrl_byte & MAX127_CTRL_RNG) ? MAX127_FULL_RANGE :
ctrl |= (MAX127_CTRL_RNG | MAX127_CTRL_BIP);
ctrl &= ~MAX127_CTRL_RNG;
data->ctrl_byte[channel] |= MAX127_CTRL_RNG;
data->ctrl_byte[channel] &= ~MAX127_CTRL_RNG;