AM3359 ICE Board (Pin Mux Problem)

Patrick Ruf

Other Parts Discussed in Thread: AM3359

Dear TI Support Team

I have just checked the AM3359 ICE Schematic (Rev. A2) and I have tried to follow the Pin assignment with the Pin Mux Utility (Version 2.2.1.0). Now I have seen the the ICE is using the ZCZ package and connects PRUTH0_RXD1 signal to pin V5. But Pin V5 is not a PR1 MII0 RXD1 pin according to the Pin Mux Utility and according to the Datasheet (sprs717b). PR1 MII0 RXD1 should connect to U3?
With ZCE package V5 would be ok according to the datasheet.

Can you tell me what's wrong and what's right?

over 13 years ago

0 Frank Walzer over 13 years ago

TI__Mastermind 44306 points

Good catch! But be assured that the ICE schematics are ok in that sense. We have tested this with our EtherCAT slave implementation.

The explanation why will be a bit lengthy... sorry.

Actually there is an additional mux internal to the PRUSS. That allows to use the above seen pins as MII0 RXDn instead of their 'normal' chip level pin-mux assignment. Details on this will be in future TRM updates. If you like to see how this is configured by software have a look at the code that comes with the industrial SDK.

For customer applications it will be possible to use the pin-mux in the normal way and configure PRUSS accordingly with an API function.

Unfortunately the additional muxing is not reflected in the pin-mux tool. I am not sure if there is a plan to ever implement that. So for now we need to document that in a better way. We have started a wiki for ICE on the external forum and I think this point needs to be added there too.

Regards.

0 Patrick Ruf over 13 years ago in reply to Frank Walzer

Genius 4965 points

Wow that was fast. I'm impressed! You must have an interrupt line and DMA to the E2E ;-)

Thanks a lot for the answer. That helped.

Best regards

0 benny_ over 13 years ago in reply to Patrick Ruf

Prodigy 40 points

Hello Frank,

We are designing a platform with ethercat, muxed GPMC and some other peripherasl: SPIs, USBs, CAN, uarts and so on.

I am really interested on the posibility that you pointed out, of using different signals of the PRU instead of the'normal' chip level pin-mux assignment. I would like to use the "additional mux internal to the PRUSS" as done in the ICE with the PRUETH0_RXD0-RXD3 lines.

I would like to route PR1_MDIO_DATA and PR1_MDIO_MDCLK and if possible PR1_MII1_TXEN and PR1_MII1_RXLINK to the U5, V5, R5, R6 pins. This way, I will we able to use de CSx muxed with the signals mentiones before and give the ethercat fuctionality to the board

Thanks for the help

0 Frank Walzer over 13 years ago in reply to benny_

TI__Mastermind 44306 points

Hi Benny,

we will have to wait for the official docs update but as far as I can see the signals you want are not covered by the internal PRU mux. So you need to use the default pin mux for them and find another solution for your CSx needs.

Regards.

0 benny_ over 13 years ago in reply to Frank Walzer

Prodigy 40 points

Thanks Frank for your support.

Where can I check the signals that are internal PRU pin muxing unit (It does not matter if it is not an official doc).

Do you have the time schedule for the release date of this doc?

0 Frank Walzer over 13 years ago in reply to benny_

TI__Mastermind 44306 points

Hi Benny,

sorry for the long delay here. The latest plan for updated PRUSS docs is to have a new docs package as part of BeagleBone by end of this month.

Regards.

0 Frank Walzer over 13 years ago in reply to Frank Walzer

TI__Mastermind 44306 points

I just found by chance that at least the PRUSS internal pin-mux is already documented in the TRM (to my surprise).

See chapter 4.4 in SPRUH73z.

No clue why no one told me...

Regards.

0 benny_ over 13 years ago in reply to Frank Walzer

Prodigy 40 points

I do not find out the doc on the web....

Can you send the link?

Thanks Frank.

0 Frank Walzer over 13 years ago in reply to benny_

TI__Mastermind 44306 points

Sorry, my fault. There was a typo in my file name and it should have been SPRUH73c. Unfortunately the doc just got updated to 'd' version and the PRU section is much shorter now. Assuming this will go into another doc in the future.

Regards.

0 Daisuke Maeda over 12 years ago in reply to Frank Walzer

Guru 20205 points

Hi Frank,

I found the document that describe about the PRUSS internal pin-mux.

am335xPruReferenceGuide.pdf

- 4 PRU-ICSS Internal Pinmux Overview

There is it in the following link.

https://github.com/beagleboard/am335x_pru_package

Is this document available for other than beaglebone?

Best regards,

Daisuke

0 Frank Walzer over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 44306 points

Daisuke-san,

the doc you mentioned is relevant for all AM335x which contain the PRU-ICSS. This is not board dependent. In the past this section was part of the TRM.

Obviously your system level and PRU internal pin mux configuration must match the board schematics. But that is software...

Regards.

0 Daisuke Maeda over 12 years ago in reply to Frank Walzer

Guru 20205 points

Hi Frank,

Thank you for the reply.

Is there the reason why pr1_mii0_rxd[3:0] were not used for ICE?

Best regards,

Daisuke

0 Frank Walzer over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 44306 points

The ICE pin-mux was based on IDK pin-mux. There we had to use the internal pin-mux trick to free up some PWM pins on the system level. Otherwise we couldn't have done the motor control application. At least as far as I can remember...

On ICE we could have changed but we just kept it that way.

0 Daisuke Maeda over 12 years ago in reply to Frank Walzer

Guru 20205 points

Hi Frank,

Thank you for the reply.

Our customer is going to design their circuit in the near future.
And that circuit design will be based on ICE.

Best regards,

Daisuke

0 Daisuke Maeda over 12 years ago in reply to Frank Walzer

Guru 20205 points

Hi Frank,

Does the latest release of ISDK support the PRUSS internal pin-mux configuration?

Best regards,

Daisuke

0 PratheeshGangadhar over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 47541 points

Hi,

PRUSSPinMux_Config API from host side can be used for configuring this.

0 Daisuke Maeda over 12 years ago in reply to PratheeshGangadhar

Guru 20205 points

Hi Pratheesh,

Thank you for your reply.

I understand that the PRUSSPinMux_Config API changes the value of the following register. Is my understanding correct?

AM335x PRU-ICSS Reference Guide
https://github.com/beagleboard/am335x_pru_package/blob/master/am335xPruReferenceGuide.pdf
4 PRU-ICSS Internal Pinmux Overview
10.1.14 PIN_MX Register (offset = 40h) [reset = 0h]

Best regards,

Daisuke

0 PratheeshGangadhar over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 47541 points

Hi,

Yes - this is correct.

0 Daisuke Maeda over 12 years ago in reply to PratheeshGangadhar

Guru 20205 points

Hi Pratheesh,

Thank you for your reply.

Best regards,

Daisuke

0 Daisuke Maeda over 12 years ago in reply to PratheeshGangadhar

Guru 20205 points

Hi Pratheesh,

Does the PRU firmware included in ISDK support the PRUSS internal pin-mux which was changed from the default setting to other?

Best regards,

Daisuke

0 PratheeshGangadhar over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 47541 points

Hi Daisuke san,

This is a pinmux configuration which we intentionally kept out of firmware - so if you select a different pinmux configuration, just make sure to configure corresponding SOC pins for this to work with SDK firmware.

In fact, newer ICE v2 EVM uses different internal pinmux than ICE v1 / IDK EVMs.

0 Daisuke Maeda over 12 years ago in reply to PratheeshGangadhar

Guru 20205 points

Hi Pratheesh,

Thank you for your reply.

I mind about the firmware run on PRU because fixed firmware included in ISDK is used for PRU.
I understand that the same PRU firmware can be used for different PRUSS internal pin-mux. Is my understanding correct?

Best regards,

Daisuke

0 PratheeshGangadhar over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 47541 points

Yes - same PRU firmware can be used for different internal pinmux configuration.

0 Daisuke Maeda over 12 years ago in reply to PratheeshGangadhar

Guru 20205 points

Hi Pratheesh,

Thank you for your reply.

Best regards,

Daisuke

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AM3359 ICE Board (Pin Mux Problem)