On 16/10/08 16:52:10, Andy Green wrote: > Somebody in the thread at some point said: > | (The first message I sent does not seem to have arrived) > | On 12/10/08 18:00:55, Andy Green wrote: > |> Yes always-on MPU can deliver consistent power behaviours we can't > do > |> in > |> our current way of relying on PMU. You would basically make the > PMU > |> a > |> slave of the MPU. Stuff like debricking scheme for a programmable > |> and > |> so brickable MPU that controls the PMU... needs careful thought. > |> > |> -Andy > | That shouldn't be a problem, because microcontrollers support in > | circuit serial programming, so just make sure we can get to those > pins > | and have a doc that specifies the programming protocol for the > brave. > > The issue is that if we allow user-updateable MPU, it can always be > bricked. So for example we put out a new package with some MPU > update > that is broken, suddenly many devices could be bricked before we pull > it. We definitely need some credible sequence of actions for the > end-user that can unbrick the devices. Just telling him where some > pins > are doesn't really cut it. > > If the MPU is master of the CPU, then when it is bricked a lot of > assets > we might otherwise call on are unavailable. So it needs thinking > through being aware of specific capabilities of the MPU. Should have mentioned that I have flashed microcontrollers for various projects that I am doing, so this was just meant for people who are used to this sort of thing rather than end users. I think you would probably want to leave MCU updates to the distributors or people who have done this sort of thing before and I suppose you would need a nano boot loader if you wanted to flash the MCU from user space (if microcontrollers that small will allow you to rewrite the flash from code). > > -Andy > Michael.
_______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
