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Registered: ‎07-31-2018

ZYNQ 7000 SoC JTAG issues w. VCCO_0 @ 3.3V

Hi, i'm having issues on a board with a ZC7Z030-2 FBV484 ZYNQ.


I've used this specific circuit in several other boards with no issues, however on this board i've run into issues, i cant get the Zynq 7000 to work properly. It is sporadically showing up in Vivado HW monitor and sometimes not at all showing via bank 0 JTAG. Programming the ZYNQ fails, so something may be wrong with the JTAG.


The main difference on this board that has issues from other working boards is that i put the VCCO_0 to 3.3V instead of 1.8V, also setting CFBVS to 3.3V etc. Specifically this is how it is powered (bold text when changed from 1.8V to 3.3V):


VCCO_0 = 3.3V

VCCO_12 (HR) = 3.3V

VCCO_13 (HR) = 1.8V

VCCO_34 (HP) = 1.8V

VCCO_35 (HP) = 1.8V

VCCO_MIO0_500 = 3.3V

VCCO_MIO0_501 = 1.8V


Some pins that also had to be changed...


RSVDVCC_1:3 = 3.3V

INIT_B, PROG_B = 3.3V via 4k7


First off i just wanted to confirm with someone that i didn't miss or frick something up with this change?


I thought i read up on the VCCO_0 @ 3.3V and saw no issue with setting it to 3.3V.

Otherwise there may be some kind of integrity issue with the JTAG chain.

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