F28M35 Rev0 vs RevB inconsistent behavior

Nigel Elliott

We have boards with Rev0 F28M35 devices and recently received boards with RevB F28M35 devices.

We are running the same code on Rev0 boards as RevB. After initial device setup we use a UART to initialize an external device then talk on Ethernet. On the Rev0 boards it takes 1.5sec to the point at which we talk on Ethernet, on the RevB boards this takes 150sec. A factor of 100.

Has anyone seen this type of behavior?

over 12 years ago

0 Gautam Iyer over 12 years ago

Guru 192875 points

Hi,

There seems to be a delay element present in RevB; check with the external crystals used. Compare the schematics and jot down the differences that you feel might've caused this delay.

Regards,

Gautam

0 Nigel Elliott over 12 years ago in reply to Gautam Iyer

Intellectual 320 points

Gautam,

There doesn't appear to be any obvious difference in the schematics. The RevB device will boot and control GPIO from both cores without an issues, but appears to hold off the EMAC interface. We have removed nearly all our code and are left with the RTOS with no change in behavior, the ethernet interface does not come up for 150sec (as seen by the speed and activity LEDS attached to the PHY device).

As a point of reference on a bare board with no software loaded the PHY device is up and registered by a switch almost immediately.

Nigel

0 Nigel Elliott over 12 years ago in reply to Nigel Elliott

Intellectual 320 points

This post is superseded by

http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/281663.aspx

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F28M35 Rev0 vs RevB inconsistent behavior