Panasonic HHC ROM 'capules'

[brouhaha]

(01-25-2023 03:23 PM)EdS2 Wrote:  Would a suitable circuit with a capacitor and a diode allow the flash to remain powered in between relatively frequent accesses? Then a delay would only be needed for the first access after some time of inactivity.

I've considered that. At first I didn't think it would be workable because there's no chip select available. However, because the HHC actively pulls the power back down, one might be able to add a CMOS inverter (powered by the diode and capacitor), and drive the flash chip select from that.

The tradeoff is using a high enough capacitance to make it work reliably, but low enough that it doesn't require so much initial charging current to cause a problem for the HHC electronics.