Omap-l138 Rev.B vs. Omap-l138 Rev.E

Pichet Ong

Other Parts Discussed in Thread: OMAP-L138, OMAPL138

We have multiple systems that run on OMAP-L138 rev.B (OMAPL138BZWT3) without any problem, recently we build up more systems that run on OMAP-L138 rev.E (OMAPL138EZWT3). We now experience system lock up with OMAP-L138 rev.E.

Error message: unable to handle kernel paging request at virtual address 60000024

Pichet

over 9 years ago

0 Shankari G over 9 years ago

TI__Mastermind 43955 points

Hi Pichet,

1. Are all the systems of OMAP-L138 rev.E gives problem or only few? Is it the same kernel image booted?

2. Are there any modifications done in the hardware design of your custom boards when it is migrated from the rev.B to rev.E?

3. Please attempt to boot the kernel image on the TI OMAPl138 EVM if you have one.

The following link may be useful to you.
www.makelinux.net/.../chp-4-sect-5

0 Titusrathinaraj Stalin over 9 years ago

TI__Guru** 116100 points

Dear Pichet,
In addition to Shankari's suggestions,

Error message: unable to handle kernel paging request at virtual address 60000024

When you are getting this error ?
While booting or accessing any particular driver ?
This kernel panic is from different driver or any particular driver ?

0 Pichet Ong over 9 years ago in reply to Shankari G

Prodigy 100 points

1. We prototype 13, 2 exhibits this behavior on the same kernel image.
2. The PCB has some changes but the OMAP-L138 and it peripheral did not change.
3. We will attempt to boot the kernel from our EVM

0 Shankari G over 9 years ago in reply to Pichet Ong

TI__Mastermind 43955 points

Hi Pichet,

1. I guess so, if out of 13, only 2 throws error, then it is not the problem with the software. By doing hardware debugging on the non-working boards compared with the working boards might help.

3. Update us on how it goes on booting the kernel on TI EVMs.

0 Pichet Ong over 9 years ago in reply to Shankari G

Prodigy 100 points

We found some issue with DDR2, where if we slow PLL1_SYSCLK1 (DDR2 interface clock source) from 150MHz to 125MHz, no error.

Questions:

1. If our CVdd core voltage set at 1.1V does that imply that PLL0_SYSCLK6 (ARM Clock) max at 200MHZ?

2. Do you know of any issue/solution what cause this error with the DDR2? We notice if we apply heat to the DDR2 the error will increase.

Thanks,

Pichet

0 Titusrathinaraj Stalin over 9 years ago in reply to Pichet Ong

TI__Guru** 116100 points

Dear Pichet,
Glad to hear that you found some workaround.
Let check with HW guy on this further follow up.

0 Shankari G over 9 years ago in reply to Pichet Ong

TI__Mastermind 43955 points

Hi Pichet,

This query has been notified to the hardware team. Thanks for your patience until they get back.

0 Senthilkumar Srinivasan over 9 years ago in reply to Pichet Ong

TI__Mastermind 43660 points

Pichet,

1. Yes, when you set the CVDD core voltage to 1.1V, both DSP and ARM frequency are limited to 200 MHz. Please refer table Table 6-5. Maximum Internal Clock Frequencies at Each Voltage Operating Point in device data manual.

2. It seems to be a system issue. Could you please swap the SoC between working and not working board and see the DDR functionality ?

There is no known issues on DDR interface and we did not face any issues with DDR2 interface clock of 150MHz.

Regards,
Senthil

0 Pichet Ong over 9 years ago in reply to Senthilkumar Srinivasan

Prodigy 100 points

This is our custom layout PCB, where the Omap-L138 is directly solder to the board. Please note that we are not only changing from Rev.B industrial to Rev.E commercial grade. Please also note that we have been using Rev.B industrial grade for a while now without any problem.

Thanks,

Pichet

0 Senthilkumar Srinivasan over 9 years ago in reply to Pichet Ong

TI__Mastermind 43660 points

Pichet,

Yes, i understand. To narrow down the issue, i wanted you to swap the chip between the working and not working board. This is to confirm if the SoC causing this issue.

Also you mentioned, when you apply heat to the DDR2 the error will increase. What is the temperature rating of the DDR2 device ? I suspect the issue might with DDR2 memory device.

Regards,
Senthil

0 Pichet Ong over 9 years ago in reply to Senthilkumar Srinivasan

Prodigy 100 points

We are unable to swap the Omap-L138 at this time due to lack of SMT rework and re-ball machine. DDR2 are commercial rated temperature part. We applied a small among of heat to the DDR2 case from room temperature to about 50C.

Pichet

0 Pichet Ong over 9 years ago in reply to Pichet Ong

Prodigy 100 points

We have now fix our DDR2 failure by changing the tRFC.
Is it ok to run CVdd and RVDD at 1.3V for 375MHz part?

Pichet

0 Mukul Bhatnagar over 9 years ago in reply to Pichet Ong

TI__Guru* 83915 points

Good to see the issue under control. As the team highlighted there is no difference in the 2 revs that should've caused your failures.

Please clarify why you want to run the 375 MHz part at a higher voltage when 1.2V is sufficient for 375 MHz operation?
Are you not concerned about power?

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Omap-l138 Rev.B vs. Omap-l138 Rev.E