OMAPL138/AM1808 at 456Mhz

SANGILI KUMAR

Genius 3920 points

Other Parts Discussed in Thread: OMAPL138

I'm working with OMAP L138 LCDK kit and i'm using linux.

How to check the ARM core running speed whether its 350Mhz or 456Mhz ?

And how to configure the ARMcore for 456Mhz.

cat/proc/cpuinfo saying that BogoMIPS : 148.88

Thanks

Sangly kumar.

over 11 years ago

0 Titusrathinaraj Stalin over 11 years ago

TI__Guru** 116100 points

Hi,

How to check the ARM core running speed whether its 350Mhz or 456Mhz ?

1) You can check the ARM core frequency by following command,

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

2) If you want to change the frequency to some other

Say ex : 456MHz

echo 456000000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

3) If you want to enable 300Mhz from starting the kernel stage then,

u-boot# set maxcpuclk 300000000

4) You can change the frequency through CPUfreq support from kernel by using OPP of OMAPL138

Note:

Ensure that you have enabled "CPUfreq in kernel menuconfig

CPU Power Management --->

CPU Frequency scaling --->

0 SANGILI KUMAR over 11 years ago in reply to Titusrathinaraj Stalin

Genius 3920 points

Hi Mr.Stalin

root@omapl138-lcdk:/# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq shows

300000

root@omapl138-lcdk:/# echo 456000000 > /sys/devices/system/cpu/cpu0/cpufreq/scal
ing_setspeed

but there is no effect its still showing

root@omapl138-lcdk:/# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq shows

300000

kindly let me know how to find the silicon specification from the silicon top view.

Below i mentioned the part specification written on my chip and please let me know the chip specification

OMAPL138

ZWT

26A76KW GI 375

21 527 ZWT

Thanks

Sangly

0 Titusrathinaraj Stalin over 11 years ago in reply to SANGILI KUMAR

TI__Guru** 116100 points

Hi,

It seems to be the default frequency has been set to 300MHz.

Select "user space" option in CPUfreq at make menuconfig option.

What is your SDK version for OMAPL138 used?

Refer the below TI wiki,

http://processors.wiki.ti.com/index.php/OMAP-L1_Linux_Drivers_Usage#Power_Management

Below i mentioned the part specification written on my chip and please let me know the chip specification

OMAPL138

ZWT

26A76KW GI 375

21 527 ZWT

http://www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=sprz301&fileType=pdf
http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=omap-l138&fileType=pdf

Please refer the chapter 6 from data sheet of OMAPL138

ZWT --> 361-Ball Pb-Free PBGA [ZWT Suffix], 0.80-mm Ball Pitch

21 --> Revision 2.1 (latest)

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OMAPL138/AM1808 at 456Mhz