Additional feedback _ I notified (+) Tushar Thakur's Profile - Tushar Thakur - TI E2E support forums from an SK-AM64B failure:

1) The AM64B Starter guide Quick Start Guide (ti.com) and the AM64x MCU+SDK User Guide (ti.com) user Documents/User Guide/EVM setup for the SK-AM64 do not explicitly mention the initial condition for the SK-AM64B SW5 . From page 39 of the schematic:

How sure is TI that the initial position of SW5 (part number AS11AP) taken from the box is in the OPEN position?  - NKK's truth table line:

The initial state and sequencing of when to open/close SW5 wrt the steps to connect the two Micro-B cables and the USB Type C power connection being applied is quite important!  The closure of SW5 disables U65 (TPS6522053 PMIC ) which disables MOST of the DC power on the SK-AM64B.

Only the AM64x SK EVM User's Guide (Rev. B) (ti.com) mentions SW5 on page 11 in section 4.3.2

2) The older SK-AM64 pictures of mode switch settings SD BOOT, NO BOOT, UART BOOT, and OSPI BOOT in the 

AM64x MCU+SDK User Guide (ti.com) user Documents/User Guide/EVM setup

seem to conflict with pictures on modes seen in 

• The AM64B Starter guide Quick Start Guide (ti.com) - SD card boot 
• The AM64x SK EVM User's Guide (Rev. B) (ti.com) - page 10 SD card boot & no boot 

This should have been cross-reference QC'd !  Which one is right?

Jim

I have reassigned this thread to the hardware team to assess. If you do no see some guidance next week , please free  to ping. 

Thanks Mukul: my new SK-AM64B is set to arrive tomorrow and I really want to know the SW5 settings so that I do not damage this one.

Hello Jim

Help me understand your query and concern.

I assume you would do a visual check to verify the switch position and configure the switch accordingly.

Regards,

Sreenivasa

Kallikuppa:

 The 1st issue is that SW5 is not defined in the SK-AM64B quick start guide to be in a certain position before UART/XDS100 traffic and/or TYPE C USB power is applied. If you do not have SW5 in the OPEN position before you powerup, none of the TPS6522053 PMIC outputs will be enabled (i.e. SW5 in a CLOSED position to GND). I would also think that keeping SW5 closed for long periods of time would be not prudent to the U65 PMIC as well as the R499 . If SW5 is meant to be used as a "momentary switch" to execute a disable, then re-enable sequence to the U65 PMIC, then something should be said in how to sequence this.

The other issue is in the inconsistency of 3 documents in the respective BOOTMODE picture settings for the AM-64B - which ones are correct??

Hello Jim

Please refer below inputs. 

I understand your concerns on the user guide documentation. I will provide feedback to the EVM team for improvement. 

Jim Mrowca said:

The 1st issue is that SW5 is not defined in the SK-AM64B quick start guide to be in a certain position before UART/XDS100 traffic and/or TYPE C USB power is applied. If you do not have SW5 in the OPEN position before you powerup, none of the TPS6522053 PMIC outputs will be enabled (i.e. SW5 in a CLOSED position to GND). I would also think that keeping SW5 closed for long periods of time would be not prudent to the U65 PMIC as well as the R499 . If SW5 is meant to be used as a "momentary switch" to execute a disable, then re-enable sequence to the U65 PMIC, then something should be said in how to sequence this.

Customers should place the switch is the closed position, which turns off the PMIC, until all of the cables are connected.  Therefore, we should be shipping the boards with switch in the closed position.  This will keep the PMIC off until the customer connects all of the cables.  

Jim Mrowca said:

The other issue is in the inconsistency of 3 documents in the respective BOOTMODE picture settings for the AM-64B - which ones are correct??

https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/latest/exports/docs/api_guide_am64x/EVM_SETUP_PAGE.html

Regards,

Sreenivasa

Kallikuppa:

 Do we have the draft documentation for the SK-AM64B's "out of the box" sequencing in the next rev of the https://dev.ti.com/tirex/explore/node?node=A__ALqhtJgGIUvD4HS9SggrMA__am64x-devtools__FUz-xrs__LATEST   for the SW5 just before/after applying the "Establishing a Serial Connection with the SK" ?

I know that the MicroB cable applies power to a portion of the SK-AM64B (ie the UART and the XDS110) before the rest of the dc power for the SK-AM64B is applied via the USB Type C connector (which feeds into the U65 PMIC).

When does one sequence the SW5 from closed (GND) to open (near VCC3V3SYS_EXT) in the process to get to "Running Linux and Demos on the SK"?

---

From the EVM_SETUP_PAGE,SK-AM64 pictures of the BOOTMODE switches, we need to also correct and/or replace those pictures currently

• in quick start guide https://dev.ti.com/tirex/explore/node?node=A__ALqhtJgGIUvD4HS9SggrMA__am64x-devtools__FUz-xrs__LATEST 
• as well as the user manual https://www.ti.com/lit/ug/spruiy9b/spruiy9b.pdf   section 4.3, figure 4.4

thanks

Jim

Hello Jim,

When does one sequence the SW5 from closed (GND) to open (near VCC3V3SYS_EXT) in the process to get to "Running Linux and Demos on the SK"?

Customers should place the switch is the closed (ON) position, which turns off the PMIC, until all of the cables are connected.  Therefore, we should be shipping the boards with switch in the closed (ON)position.  This will keep the PMIC off until the customer connects all of the cables.  

I am not sure if there is a recommended timing before the switch needs to be OFF.

Regarding the documentation, let me check and update.

Regards,

Sreenivasa

Kallikuppa:

Yes your PCB assembly supplier does need to ship the SW5 in the ON position!

For the record this photo snip was the state of SW5 (on the bottom) on that newest SK-AM64B EVM that arrived yesterday -- looks like this was shipped with SW5 OFF!

You might want to issue an FAQ entry on this SW5 setting

(cc (+) Mukul Bhatnagar's Profile - Mukul Bhatnagar - TI E2E support forums   )

Can you also please find out if the BOOTMODE switches on the SK-AM64B are consistently shipped in the default positions (and what mode) as in the photo?

Has anyone at Mistral and/or TI India know why the SW5 was implemented in the first place?

later

Jim

Hello Jim, 

Thank you for the inputs.

Jim Mrowca said:

Yes your PCB assembly supplier does need to ship the SW5 in the ON position!

For the record this photo snip was the state of SW5 (on the bottom) on that newest SK-AM64B EVM that arrived yesterday -- looks like this was shipped with SW5 OFF!

Thank you updating the observations. This helps improve EVM quality.

Let me check with the EVM team but i suspect we have a  default configuration for the bootmode that is ensured before shipping.

We expect customer to configure the required bott during startup.

I will provide this as a feedback for improvement.

Jim Mrowca said:

You might want to issue an FAQ entry on this SW5 setting

Noted. Will provide the required feedback to the EVM team.

Regards,

Sreenivasa

Sreenivasa: Here is a discrepancy between 2 artifacts (the one on the left works as is out of the box)  attached slide  

Why are these 2 SD BOOTMODE settings not the same.pptx

Hello Jim, 

Thank you for the additional inputs.

The discrepancy is not expected.

I will check with the team and have this updated.

Regards,

Sreenivasa

Hello Jim,

Jim Mrowca said:

Has anyone at Mistral and/or TI India know why the SW5 was implemented in the first place?

I suspect this would be part of the SK improvements.

Can you help me understand the use case for the query.

Regards,

Sreenivasa

Sreenivasa,

 It is more so a question as to why is the U65 PMIC needing the enable initialization implemented with a slide switch - essentially TI should have documented that SW5 more explicitly so that user confusion on and/or damage to the SK-AM64B could be avoided.

I can now see why after the discussions we need that, as well as the ability to also control that signal by the TEST_POWERDOWN signal (input from a test automation J16 connector on the bottomside). 

I suspect someone did not want to use a momentary switch instead of a slide switch on SW5. Just from my experiences, I would not want to have a PMIC output disabled (by an enable signal) for quite a long time, given most of the AM6442's dc power is supplied & sequenced by that PMIC.

thanks

Jim

Hello Jim,

Thank you for the additional inputs.

I will provide the inputs to the EVM team for making the required updates and including the details.

Jim Mrowca said:

Here is a discrepancy between 2 artifacts (the one on the left works as is out of the box)  attached slide  

Why are these 2 SD BOOTMODE settings not the same.pptx

FYI, we tested the SK-AM64 with both the bootmode configuration and it seems to work.

I suspect this depends on the SD card format etc.

You inputs are noted on the bootmode configuration related explanation for improvement.

Regards,'

Sreenivasa

Sreenivasa:

I have attached another powerpoint also showing some documentation confusion on BOOTMODE settings for NO BOOT as well as SD BOOT  SECOND_Why are these 2 SD BOOTMODE settings not the same.pptx

Hello Jim,

Thank you for the additional inputs for improvement.

I will provide the inputs to the design team and the EVM team.

Regards,

Sreenivasa

Kallikuppa:   The SW5 switch position is now sufficiently documented on the SK-AM64B schematic in last month's release of sprr460c.zip .  We should keep this e2e open to ensure the other documents referenced are updated.

thanks, Jim

Hello Jim,

Thank you for the note.

Regards,

Sreenivasa