GreenPAK GPIO Expander

Choosing GreenPAK™ at the very beginning of your project is a perfect decision to avoid unforeseen issues from the start. Choosing an MCU with the exact right amount of IO at the beginning of a project may be difficult as new requirements often creep in and some unforeseen engineering challenges occur during development. Adding differentiation to your project can be challenging as well since most MCUs available are available to everyone.

Many new GreenPAK devices include an I²C block which makes these components perfect for an ideal GPIO expander allowing you to add new features, logic, timing, and sensing to already highly integrated designs.

GreenPAK Benefits as GPIO Expander

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Expanding GPIO

Using GreenPAK's I²C block allows for easy expansion of both input and output. With simple I²C commands the matrix input of each component on the chip, including the GPIO, can be read, expanding input. With simple I²C write commands, I²C virtual inputs can push digital signals into the device or directly to GPIO.

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I2C Virtual Inputs

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I2C Readable Matrix Inputs

Key Design Considerations

• IO Configuration
  Configurable pull-up/pull-down resistors on GreenPAK's GPIO make communicating with any IC a snap.
• Initial values
  Using GreenPAKs OTP NVM, it is easy to set initial output values
• Latching during Write
  GreenPAK can be set to latch IO during write or update values as soon as a bit is written
• I2C Speed
  GreenPAK I²C is 400 kHz
• I2C Address
  GreenPAK I²C can have up to 16 unique addresses
• Timing Adjustment and Additional Glue Logic
  GreenPAK has integrated LUTs, Inverters, DFFs, Counters

Resource Utilization

GreenPAK can often implement multiple functions in one small device. This isn’t limited to GPIO expansion applications. Just one GreenPAK device can implement glue logic, timing adjustment, reset, power sequencing, LED control, and more depending on design requirements and resource configuration.

All GreenPAK 5 devices contain the needed I²C block for GPIO expansion and are only limited by the number of pins. Below is a chart of the maximum number of direct inputs or outputs achievable for each member of the family.

GreenPAK GPIO Expander Demo Board is available for purchase. Please email us at [email protected] to learn more details.