12Mhz clock signal on CS1

Stan Sidorov

Expert 1985 points

Hi there,

I have just received a new custom board based on C5535 core. When I am trying to debug it with the emulator it gives me a error message:

C55xx: Error connecting to the target: (Error -1069 @ 0x0) Device memory bus has an error and may be hung. Verify that the memory address is in valid memory. If error persists, confirm configuration, power-cycle board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 6.0.14.0)

So I looked though the schematics and layout and did not find anything weird. Everything is made according to TI recommendations. Than I found 12Mhz clock signal on CS1(pin M2). I am pretty sure that there is no actual short on board(checked that) and this signal somehow goes through the DSP. I am lack of ideas what it might be. Any suggestions will be appreciated.

Thank you.

Stan

over 10 years ago

0 Vasantha K over 10 years ago

TI__Genius 12575 points

Hi,

Is clocks enabled to the respective peripherals (check PCGCR) ?

Were you able to single step and if so, where exactly are you getting this error ?

Also, hope you are aware of this wiki link.

Regards

Vasanth

0 Stan Sidorov over 10 years ago in reply to Vasantha K

Expert 1985 points

Vasanth, thank you for your reply.

I do not have an access to the any register. So the core stuck right after the power up. It even does not toggle CS0 as it should according to the Bootloader Initialization procedure. So everything that I can observe is there is a 12Mhz clock on CS1 right after powering up.

Thank you.

Stan

0 Stan Sidorov over 10 years ago in reply to Vasantha K

Expert 1985 points

Vasanth, we have two ideas of why 12Mhz clock appears on CS1:

1. DSP switched over some kind of test mode which was not documented for customers.
2. The chip is fake.

We checked schematics, layout, gerber files and all lines on actual board. Everything is looking good. We even tried to short CS1 to 3.3V to check if it effects CLKIN with 12Mhz but it did not. It is clear that DSP is a source of 12Mhz on CS1 line.

Any other suggestions will be very appreciated.

Stan

0 Vasantha K over 10 years ago in reply to Stan Sidorov

TI__Genius 12575 points

Stan,

With respect your ideas.

1. I do not think so.

2. Can you let us know the exact part number (printed on the device).

How many custom boards do you have, is there any 2nd board that you can perform this test on?

Let me also look at the issue further and get back.

Regards

Vasanth

0 Stan Sidorov over 10 years ago in reply to Vasantha K

Expert 1985 points

Vasanth,

We have 10 boards and all behave the same. The part number from one of the DSPs is TMS320C5535AZHHI04BAQ5RW

Thank you.

Stan

0 Stan Sidorov over 10 years ago in reply to Stan Sidorov

Expert 1985 points

What we found is the oscillator produces too much noise. Even high quality oscillator that we tried did not work. So we just filtered it placing 220Ohm resistor in serial.

0 Vasantha K over 10 years ago in reply to Stan Sidorov

TI__Genius 12575 points

Hi,

Thanks for the update. Glad to know that,the issue got resolved.

Regards

Vasanth

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12Mhz clock signal on CS1