Thanks for reply.
Pls. specify the power domain for VROUT pin and EXT_WAKE as it is not mentioned anywhere in datasheet and hardware reference.
I confirmed it. Voltage regulator start right after the VDDEXT is up and RESET is asserted. So during the period of RESET assertion the regulator will generate VROUT so that VDDINT can be generated.
I hope this clarifies your doubts.
I have branched this post, and moved it to the Blackfin Processors community, as your question is no longer specific to the EZ-KIT Lite, but a general BF548 one.
Please continue the discussion here.
I am not really sure but I think it should be VDDEXT domain
This is a branched discussion, the actual discussion goes like this:-
I want to know the sequencing related to VDDINT rail.
1. Because EZ-Kit Lite is using internal regulator controlled through VROUT pin.
2. So during power on reset, to follow the power sequencing as stated on page-42 of Datasheet says that reset should be de-asserted only after all Power domain rails are stable.
3. So how can VDDINT be generated as it is controlled through VROUT pin, which cannot work because processor is still in reset?
So does VROUT pin belong to always powered domain and have no effect of reset?
Internal voltage regulator require only VDDEXT(not VDDINT) supply and the regulator works even while RESET pin is asserted.
So once VDDINT, VDDEXT are stable the RESET should be kept asserted for a minimum period of 3500 CLKIN cycles. This is taken care of using a reset supervisory circuit.
To generate VDDINT, VROUT pin (connected to external switcher) need to be functional, but this cannot happen as processor is in reset, so VDDINT cannot be generated till VROUT pin starts working which can only happen when BF548 is out of reset.
And datasheet states that reset should be asserted till all supplies including VDDINT are up.
So this means VROUT is functional even in reset and making VDDINT from VDDEXT, so that reset sequence can be followed?
Yes, that should be the case.
Can you please confirm.
Let me confirm it from the internal team and will update you once I get the confirmation.
Retrieving data ...