Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Timing analysis of the I/O processes

Hello i have a device driver that comunicates with an onchip mem. I need to see how much time it takes to read and write from the onchip mem. I've put several printk's with timestamp to debug how...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

This is probably not very accurate, as the timestamps depend on the system timer which has a low resolution (could even be 10ms). Besides if you call printk() inside the critical part of your code it will slow it down considerably.

If you need something more accurate, have a look at the performance counter (chapter 34 of this guide (http://www.altera.com/literature/ug/ug_embedded_ip.pdf)).

application note 391 (http://www.altera.com/literature/an/an391.pdf) can also be an interesting read for you.