TMS570LS3137: On the state of the pin after reset v2

Sh.Sasaki

Guru 13625 points

Part Number: TMS570LS3137

Hi everyone,

If the device revision changes, will the pin states change after device reset?

After resetting, my customer board's C13 pin will be High for a moment as follows.

The TMS570LS3137 on my customer's board is Rev.D, and this C13 pin is in Open state.

In the case of TMS570LS3137 HDK, the problem is not reproduced as described in the following link. The HDK's device revision is RevB.

https://e2e.ti.com/support/microcontrollers/hercules/f/312/t/778304

Is there a problem like this due to differences in device revisions?
I want to know what the cause is.

Best regards,

Sasaki

over 6 years ago

0 Miro over 6 years ago

TI__Mastermind 21425 points

Hello Sasaki,
Let me check this again.

Best regards,

0 QJ Wang over 6 years ago

TI__Guru**** 197126 points

Hello Sasaki,

The C13 is EMIF address signal by default. There is no pull-up and pull-down for this output pin. Is there a pull resistor on this signal on your customer's board?

0 Sh.Sasaki over 6 years ago in reply to QJ Wang

Guru 13625 points

Hi Wang-san,

Thank you for your support.

QJ Wang said:
Hello Sasaki,

The C13 is EMIF address signal by default. There is no pull-up and pull-down for this output pin. Is there a pull resistor on this signal on your customer's board?

There is no pull register. Also, nothing is connected to this pin.

In other words, it is the same as the HDK circuit.

The only difference is the device revision.

Best regards,

Sasaki

0 QJ Wang over 6 years ago in reply to Sh.Sasaki

TI__Guru**** 197126 points

Hi Sasaki,

During reset, this pin (C13) is pulled down. After the reset is release, the pin is in floating. It can be high or low. This behavior should not affect the memory attached to EMIF since the EMIF chip select should be in HIGH state (external pull-high resistor is required for CS).

0 Sh.Sasaki over 6 years ago in reply to QJ Wang

Guru 13625 points

Hi Wang-san,

Thank you for your support!
I got it.
Beest regards,
Sasaki

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TMS570LS3137: On the state of the pin after reset v2