Re: [OPEN] Bitmine CoinCraft A1 28nm chip distribution / DIY support
Having some trouble with getting 0x04 responce on the 0x04 reset command.
I'm doing the HW reset as described. The signals from raspi passed through level shifters.
Chip select DI CLK are ok. I see 0x04 passing into the chip but there is nothing at the output.
The VDDcore is 0.7 volts. Maybe it is too low?
I'm doing the HW reset as described. The signals from raspi passed through level shifters.
Chip select DI CLK are ok. I see 0x04 passing into the chip but there is nothing at the output.
The VDDcore is 0.7 volts. Maybe it is too low?
That's pretty likely too low. I had similar issues when I was running the chip that low. 0.8V seems to be pretty reliable for at least basic comms for most chips. A couple wouldn't hash at that voltage but once I brought it up to about 0.84V they were fine.
Of course, now those chips run hotter than the others
I have just tested with 0.84V. Still no responce.
zefir mentioned earlier that at the startup chip is configured at 12MHz reference clock. And the SPI speed must not be > system clock. I wounder what is the PLL multiplier at the startup to calculate the system clock.
Or maybe it doesn't matter what SPI speed to use for initialization? I guess what i wrote above is applied to SPI speed between the chips not between uC and 1st chip.
Currently when i run cgminer i see 500khz SPI speed. Is that sufficient?