ud1127L1 c5 Package Marking

Technical discussions around xCORE processors (e.g. xcore-200 & xcore.ai).
Post Reply
ds1982
New User
Posts: 3
Joined: Sat Apr 28, 2018 6:28 pm

ud1127L1 c5 Package Marking

Post by ds1982 »

Hi community,

i need to know something about a µController which has the package marking

ud1127L1 c5
p4v169.00

Can anyone tell me which Processor it is or point me to the Datasheet?


User avatar
mon2
XCore Legend
Posts: 1913
Joined: Thu Jun 10, 2010 11:43 am
Contact:

Post by mon2 »

Design has external USB PHY? Will be a common USB audio reference design based on the XMOS XS1 processor:

https://www.xmos.com/support/silicon?product=15400

Count the pins on the device to find your match.

Search for keywords XS1 USB to find all the required details. You can now create a leaner design with XCORE-200 devices with an internal USB phy.
ds1982
New User
Posts: 3
Joined: Sat Apr 28, 2018 6:28 pm

Post by ds1982 »

yes, design has an external USB PHY.
Thank you.

It is definitely an audio design, which i need to repair, unfortunately the USB is not enumerating on the PC anymore. The USB PHY is working, but always held in Powerdown by the XMOS CPU.
Thanks to the Datasheet i can investigate all components around the XMOS CPU now and hope to find something broken, which is not the CPU itself :-(
User avatar
mon2
XCore Legend
Posts: 1913
Joined: Thu Jun 10, 2010 11:43 am
Contact:

Post by mon2 »

Short list of the part as follows..

https://www.xmos.com/support/silicon/pc ... nent=16380

Review the parts with -C5 in markings and same pin count to find your match.
ds1982
New User
Posts: 3
Joined: Sat Apr 28, 2018 6:28 pm

Post by ds1982 »

found my part. thx.
User avatar
mon2
XCore Legend
Posts: 1913
Joined: Thu Jun 10, 2010 11:43 am
Contact:

Post by mon2 »

1) Did the same PC work at anytime with this XMOS audio product? If not, consider to test with at least with another PC & other USB ports to rule out the host PC as the issue.

2) Check with other known good USB data cables. There are many USB cables that are not USB 2.0 compliant or worse yet, are charging only cable so the D+ / D- signals will be missing to the host PC and respectively, fail to enumerate. Ideally seek out a USB 2.0 HS certified and branded cable. The XMOS IP does makes use of USB 2.0 speed of 480 Mbps. Shorter the cable, the better. If possible test with 1 ft (or so) length.

3) Check the power supply and clock sources. The XMOS devices do demand specific power sequencing order. Failure of this will lead to quirks like you have noted or worse. The design should have a power on reset supervisor which is open drain output and when the power supplies power up in the proper order, the POR output will tri-state but with the pull-up, apply a weak high to release from reset.

4) Do you see any activity on the XMOS port pins? The XMOS CPU is a fast bit banging GPIO machine. The XMOS IP bit bangs to communicate with the USB PHY. If not activity, then check the local and external flash device for any activity on power up. Do you see the CS on the flash doing anything? That is step # 1 to monitor which should be dancing due to the XMOS architecture.

5) The XMOS CPU often feature a metal belly so be aware that if you do wish to replace it, then a hot plate will be required with lots of patience. Do not assume this is the issue yet.

6) Are you confident that the USB PHY is ok? I would be really surprised if the design features any USB ESD protection. It is possible that the USB PHY got it due to ESD or perhaps USB in-rush current from the Vbus rail. Only the recent XCORE-200 designs mention this as an errata to place components to limit the in-rush current on Vbus. So often, it is the Vbus rail coming directly into the design.

Assuming this is an off-the-shelf product from a 3rd party with no schematics? Most have followed the XMOS supplied reference designs verbatim so you should be in good company to review the XMOS IP.
Post Reply