SLAS986D November 2014 – February 2018 AMC7836
The AMC7836 device includes eight GPIO pins, each with an internal 48-kΩ pullup resistor to the IOVDD pin. The GPIO[0:3] pins have dual functionality and can be programmed as either bidirectional digital I/O pins or interrupt signals in the GPIO configuration register (address 0x12). The GPIO[4:7] pins are dedicated GPIOs. Table 4 lists the dual function of the GPIO[0:3] pins.
|PIN||DEFAULT PIN NAME||ALTERNATIVE PIN NAME||ALTERNATIVE FUNCTIONALITY|
|7||GPIO0||ALARMIN||DAC clear control signal.|
|8||GPIO1||ALARMOUT||Global alarm output.|
|9||GPIO2||ADCTRIG||External ADC conversion trigger.|
|10||GPIO3||DAV||ADC data available indicator.|
The GPIOs can receive an input or produce an output. When the GPIOn pin acts as an output, the status of the pin is determined by the corresponding GPIO bit in the GPIO register (address 0x7A).
To use a GPIOn pin as an input, the corresponding GPIO bit in the GPIO register must be set to 1. When a GPIOn pin acts as input, the digital value on the pin is acquired by reading the corresponding GPIO bit. After a power-on reset (POR) or any forced reset, all GPIO bits are set to 1, and the GPIOn pins have a 48-kΩ input impedance to the IOVDD pin (see Figure 60). The unused GPIO pins can be left floating.