Non-Connection of VSYS

Announcements

Live Webinar: USB-C adoption. Simple & Cost-efficient solutions | April 18th @9am or 5pm CEST. Register now !

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

Hello,

In CYPD3125-40LXQI, when VBUS is directly ant unfortunately provide from internal system power source, can we open VSYS pin?

In that case, when we try to debug our software through SWD, do we need any especial sequence which is difference in a case of providing VSYS from VTARG?

Best regards,

0 Likes
6 Replies
ShifangZ_26
Moderator
Moderator
Moderator
10 likes given 250 sign-ins 1000 replies posted

Hi Takeshi-san,

1. You can open VSYS pin. The firmware default setting is, CCG3 get power from VSYS first, if VSYS is not powered on, VBUS is the second power source for CCG3.

2. The power sequence of VTARG shall be follow SWD programming SPEC. And SWD programming SPEC have difference power setup.

Best Regards,

Lisa

0 Likes
Anonymous
Not applicable

Hello Lisa-san,

Thank you for your prompt replay.

> 2. The power sequence of VTARG shall be follow SWD programming SPEC. And SWD programming SPEC have difference power setup.

This mean that I cannot debug FW from SWD programmer or debugger such as Miniorog3 if I keep to open VSYS?

Best regards,

Takeshi

0 Likes

Hi Takeshi,

You still can debug FW from SWD programmer, since the VTAG will power on VSYS if you are connected VTAG to VSYS.

Best Regards,

Lisa

0 Likes
Anonymous
Not applicable

Hello Lisa-san,

Yes, if VTARG power on VSYS, We can debug FW from SWD programmer.

if VBUS is provided 5v power, VSYS can keep to opn. so we will open VSYS.

By the way, if VBUS connect to 5 volt source which is always provided by user system and VSYS, however, does not provide from any source, Can we debug FW?

Or, Does VTARG have to connect VSYS?

________

      VBUS |-- v5

      VSYS |-- open

--------------

Best regards,

0 Likes

Hi Takeshi-san,

As per my test results, the SWD programming cannot complete if supply VBUS with 5V only. Please kindly connect VTARG of MiniProg3 to VSYS.

Best Regards,

Lisa

0 Likes
Anonymous
Not applicable

Hello Lisa,

On CY4531, I also tried to check.

J3 1-open, 2-GND, 3-VBUS

J4 1-open, 2-3 connected

I can download my program from programmer.

It is succeed.

What is my problem to check it?

Best regards,

0 Likes