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Everything ARM and LPC
By tokugawa

I'm considering STM32 for my hobby. GPIO speed is fundamental feature for me. I have tested that LPC2148 Fast GPIO could switch output on single cycle - soo.. if you have 72Mhz, you can produce 'square' wave at 36Mhz (linear set,clear,set,clear code)

There are many clocks dividers for GPIO for STM32 - but does someone done such test for STM32 ? They say that APB2 is the fastest one - can it match a FGPIO from NXP ? :)

Thanks for any info.
By Analyzer
Dear tokugawa,

Sorry it is not related with your question but i'm desperate, i couldn't get square wave faster than 3,5 mhz with fpio. I'm using Keil Realview and Keil MCB2140 ev. board. I will be faithful if you can supply me some sample code. TIA,

User avatar
By viskr
The LPC2148 is going on 8 years old now, so there are faster parts in NXPs quiver.

The LPC43xx line has clock rates of 204 MHz and the FIOs will probably toggle 3x the LPC2148. It also has a SerialGPIO that is a bank of configurable shift registers that run up to the 204 MHz rate.
By hsutherl
Just now noticed the dates on the first two posts. I guess this isn't a burning issue. :) Anyway, I checked an stm32F4Discovery (168MHz) and it can indeed push a new value to GPIO every 6 nsec, assuming you already have the desired value(s) in (a) register(s).
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