Posts: 4
Registered: ‎04-30-2016

SI468x failing to start

I have been working on my SI468x project for a few years now and while I am an amateur I believe I have finally gotten close to getting the board to boot. I have been unable to get the miniboot patch to work so that I can flashload the full patch however the full boot patch is small enough to send over its not that much of a problem. I am currently communicating with the chip using python using a serial driver to a ft232h which then communicates with the si4689 over i2c at 400khz. I have a flash chip with some programming headers but otherwise connected only to the si4689 chip. I have confirmed communication with the chip using logic analyzers.


My current problem is that on first power up (~ 1ms after stable power) I check status and get

0: 10101010
1: 1011011
2: 1111011
3: 1111011

I issue the powerup command with appropriate values and get back

0: 10000000
1: 1111111
2: 11111111
3: 11111111

I am slightly worried about status1-status3 being nothing but 1's

I issue LoadInit and get

0: 10000011
1: 00000000
2: 00000000
3: 10111100

Which appears to be cleaning up

Finally I send  the full boot patch as a hostload and get back

0: 10000000
1: 00000000
2: 00000000
3: 10000000

This gives me hope as it looks completely clean and I can see the powerup state is set to boot and I have a CTS and no err bit.

I issue another LoadInit

0: 10000000
1: 00000000
2: 00000000
3: 10000000

Still clean Then no matter if I do a flashload or a hostload of the firmware and then a final boot command I get back nothing but zeros for status request and no response for any other commands sent. Have I somehow blown the chip or am I sending something wrong perhaps ?

Posts: 77
Registered: ‎02-15-2015

Re: SI468x failing to start

Did you verify your circuit design is electrically correct (according to Silicon Labs recommendation in Application notes)?

Also, did you verify all supply voltages to Si4689 chip?


Best regards,