Datasheet

GPIO Specifications
August 2016 Intel® Joule™ Datasheet
Document number: 566641 rev. 1.0 Page 26
11.2 Digital microphone ports
Intel® Joule™ supports microphones that use the PDM digital microphone standard and attached to the module through the
AVS_M interface. Two microphones can share one data line by using time domain multiplexing to the two slots.
PDM microphones are enabled and disabled by the clock signal. Absence of clock signal will switch microphone to sleep
mode, which can be utilized in system power management.
Additionally the microphones can be power-gated to cut the power consumption to zero when microphones are not used.
Refer to the Intel® Joule™ Expansion Board Design Guide for the specifications and PCB routing guidance for this interface.
12 GPIO Specifications
12.1 Dedicated GPIO lines
The Intel® Joule™ module provides 8 dedicated GPIO lines (GPIO_0 - 6, GPIO_17 and GPIO_22) connected to the core
processor.
12.2 Reconfigurable interfaces buses as GPIO
Many interface lines on the module can be reconfigured as GPIO lines by defining a configuration table stored within an
EEPROM device on the expansion board.
The BIOS loads a default configuration (see BIOS release notes for more details) if the EEPROM appears empty or is found
unreadable by the BIOS. The configuration EEPROM is only read at cold boot and the configuration is retained during reset.
Specific outputs can be can be set or cleared before entering a sleep state.
12.3 GPIO internal pull UP / pull DOWN resistors
Each GPIO line can employ an internal pull UP or pull DOWN resistor, this is also defined within the configuration table and
stored in the expansion board EEPROM device and read by the BIOS at cold boot.
See the Intel® Joule™ BIOS Guide for pull UP and pull DOWN configuration details and the Intel® Joule™ Expansion Board
Design Guide for the specifications and PCB routing guidance of the GPIO interfaces.