Key-Matrix with Serial GPIOs (SGPIOs) ?

[lpcware]

Content originally posted in LPCWare by Martin84 on Tue Mar 18 10:30:07 MST 2014
I want to read a Key-Matrix with the LPC4357. Therefore I wanna activate the rows sequentially and read the status of the columns. If a key is pressed the column line activates a group interrupt. In the Interrupt-Routine I can read which key is pressed.

So I first thought about using only GPIOs for column and rows. But then I read something about SGPIOs.

Is it advantageous to use SGPIOs for driving and reading a Key-Matrix? Is there an example for a Key-Matrix with SGPIOs?

Regards,

Martin 

[lpcware]

Content originally posted in LPCWare by xianghuiwang on Wed Mar 26 10:32:07 MST 2014
Hi, Martin84,

It is possible using the SGPIO can save some CPU bandwidth. You can configure the different rows as individual inputs to a parallel bus on the SGPIO.
There is however no example for a Key-Matrix with SGPIO.
Suggest you read the user manual for SGPIO parallel input as well as AN11343 for the SGPIO parallel bus configuration.
Good luck!