Reading a free running timer register on DM8148

Abdurahman Alfeky

Hello,

I would like to read any free running timer on DM8148. I tried to read TCRR (@ address 0x4804603C) but it is zero all the time !!?. ( assuming that timer is configured and running)

I am not sure if this address is correct or not. The timer register offset is 0x3C.according to TRM

So, what is the correct base address of timer registers in dm8148 ? i choose this address based on info from this post

if i need to configure a free running timer to just get time stamps from it which timer should i use? and what is the right configuration ?

any help or guidance is appreciated. Many thanks

over 14 years ago

0 Sandeep R over 14 years ago

TI__Prodigy 550 points

Abdurahman,

If the TCRR is reading as zero, it may be that the timer configuration (timer register programming, muxing) is incorrect.

the base address of all the timers should be a part of the TRM. The address you are using is correct.

You can use any of available timers as a free running counter. What is the configuration you are using?

Regards, Sandeep

0 Abdurahman Alfeky over 14 years ago in reply to Sandeep R

Prodigy 60 points

Hello Sandeeb,

Actually i am reading TCRR during runtime using breakpoints with option Execute gel expression ( i do this because am trying to profile the code) . Timer configurations should be previously initialized (my system is large and DSPBIOS used) .

Anyway, would you please provide with the proper configurations to configure any GP timer? I prefer to use TIMER8 or TIMER1 as they don't have any external connections.

Many Thanks

note: i couldn't find the base addresses of timer register in TRM just the offsets! Update: Found in datasheet (sprs647c) not TRM (sprugz8)

0 Sandeep R over 14 years ago in reply to Abdurahman Alfeky

TI__Prodigy 550 points

Hi Abdurahman

It is good that you have found the base address details from the TRM.

The timer section in the TRM - http://www.ti.com/lit/ug/sprugz8/sprugz8.pdf, explains the details on the timer configuration to some extent. You can go through it to see if this helps.

0 Victor Chan over 14 years ago in reply to Sandeep R

Intellectual 795 points

I needed something that can do uSecs so I used the Performance Monitor Register of the Cortex-A8.

0 Abdurahman Alfeky over 14 years ago in reply to Victor Chan

Prodigy 60 points

Thanks Vector for this info. but how to access this register in dm814x a8 core ? i didn't found any details about it in TRM ! any suggestions?

0 Victor Chan over 14 years ago in reply to Abdurahman Alfeky

Intellectual 795 points

It is not in the TRM. You have to got to ARM website and download the Reference Manual for the Cortex-A8. This Performanace Register is similar to the cache registers, cp15.

This register counts the number of system clocks. There is an option to divide by 64 which I used . This allows for a longer period of time before it turns over since it is only a 32 bit counter.

0 Jeff L over 14 years ago in reply to Victor Chan

TI__Expert 5960 points

Abdurahman,

You can search the entire arm site to find articles and related forum posts. I found this article: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/17587.html

and this forum post: http://forums.arm.com/index.php?/topic/14532-using-cortex-a8-performance-counters/

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Reading a free running timer register on DM8148