DM8168 Best way to access hardware timer

MathiasBuder

Hi,

for a current project I want to use one of the available hardware timers insie the DM8168 to measure the hold-up time of our power supply. For that I want to have the timer running at a preiode of 100us. Inside the Interrupt handler I want to write the current time of the timer to a file.

My question is now, is there any driver support from user-space? I found the support thread below but haven't been able to implement it myself that way.

I'm looking Forward to any help!

over 9 years ago

0 Karthick Kumaran A S V over 9 years ago

Intellectual 875 points

I hope you are using EZSDK. If yes, you can use the timer available in Cortex-M3 and can write to DDR as M3 don't have access to filesystem. One of your process in the user space can periodically read the shared DDR location and write it to file. But timers in M3 have a precision in ms instead of microseconds.

0 MathiasBuder over 9 years ago in reply to Karthick Kumaran A S V

Intellectual 300 points

Hi,

I'm using DVRRDK_03.50.00.05. Would you be so kind to give me some code guidance on how to utilize the Cortex-M3 timer.

Thanks

0 MathiasBuder over 9 years ago in reply to Karthick Kumaran A S V

Intellectual 300 points

Hi,
is there actually driver support in linux for the hardware timers or do I have to use the mmap() function to map the physical address space of a specific timer module to Userspace and manipulate its registers?

0 Pavel Botev over 9 years ago in reply to MathiasBuder

TI__Guru**** 170625 points

Hi Mathias,

See if the below wiki pages will be in help:

processors.wiki.ti.com/.../TI81xx_PSP_Porting_Guide
processors.wiki.ti.com/.../TI81XX_PSP_04.04.00.02_Feature_Performance_Guide
processors.wiki.ti.com/.../TI81XX_PSP_04.04.00.02_Feature_Performance_Guide
processors.wiki.ti.com/.../BIOS_FAQs
processors.wiki.ti.com/.../BIOS_dmtimer_configuration_for_TI81xx

Regards,
Pavel

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DM8168 Best way to access hardware timer