The MAX1343 features four GPIO pins: GPIOA0, GPIOA1, GPIOC0, GPIOC1. To program the GPIO ports, two 16-bit commands are required. The first command goes to the GPIO Configuration register, which sets each port as either a push-pull output, or a tri-state input/open-drain pull-down. The second command goes to the GPIO Write register, which sets the push-pull level, or selects between the tri-state input or open-drain pull-down. To set up GPIOC1 as a logic high output, the following commands must be sent (with /CS toggling between the two 16-bit commands): 0000 0011 1000 0000 0000 0010 1000 0000 In the first command, 0000 0011 is the command byte to access the GPIO Configuration register and 1000 0000 configures GPIOC1 as a push-pull output by writing a '1' to the GPIOC1 bitfield. In the second command, 0000 0010 is the command byte to access the GPIO Write register and 1000 0000 configures GPIOC1 as an output high by writing a '1' to the GPIOC1 bitfield.