AnsweredAssumed Answered

Blackfin 527 custom system & multiple power domains

Question asked by Robert.S on May 23, 2013

Hi everyone,


I am currently developing custom board with Blackfin 527 (ADSP-BF527KBCZ-6) and I need to ask for your help.

The system will have multiple power domains and is designed as HDI PCB so no place for error.

Vddext = 1.8V

Vddmem = 3.3V

and obligatory: Vddint=1.2V, Vddrtc=3.3V, Vddotp=2.5V, Vddusb=3.3V


The main question has raised from the topic:

The topic concerns BF526. Prashant stated there:

"In the Specification section in datasheet, the footnote-6 states that RESET signal is 3.3V tolerent. Probably that is why the Reset signal in EZ-KIT is connected to 3V. But actually when VDDEXT is 1.8V, the reset signal is tolerent till 2.5V. I believe, the note will be modified in the next revision on document.   In your board, you can have reset signal of 1.8V when VDDEXT is powered with 1.8V."


1. As BF526 and BF527 are from the same family (same datasheet) is this error in specification related also to BF527? (I believe yes)

2. Is it related to all pins mentioned in footnote 6? (RTXI, TCK, TDI, TMS, TRST, CLKIN, RESET, NMI, and BMODE3–0, PF15–0, PG15–0, PH15–0) The most important pins for me are CLKIN and NMI (in my design they are connected to 3.3 driver).

3. What about USBXI clock input? I assume it is 3.3V operational as USB unit is powered form 3.3V?


Could anyone from Analog confirm that issues for all processors from BF52x family? Our project is suspended until confirmed info.

I will appreciate your help.


Best regards,





Message was edited by: Robert Strakowski

I crossed out some text to make the question more clear and straightforward.


Message was edited by: Robert Strakowski

As I am very tied on schedule and need confirmed answer from ADI I moved the problem to the private support channel.

Sorry for the inconvenience.


Best regards,