----- Ursprüngliche Nachricht ----- Von: Przemek Klosowski Gesendet am: 02 Mai 2011 19:29:22
> As described in SLAU321 (p. 187) the development version's loader > starts by outputting a pulse train on a pin, for the external charge > pump that produces enough voltage for an external SPI memory that the > bootloader then reads in. I think that is enough for a small > standalone system. The users guide wasn't online when I first (and last) looked at the device. The need for external components or a large order count was disqualifying the 092 for my projects. SO I didn't look too close at it. Anyway, the requirement of an external flash and boost regulator isn't really a standalone system. It might be of interest for small projects. IMHO, it isn't, however, a suitable approach for prototyping, since it doesn't allow developing on the same system you use later in mass production. At least there's a breakout connector required for the flash and the boost regulator (which you don't need later in the mask programmed version). Also, the bootup process is different (timings etc.) > As you say, the ROM version requires several k$ NRE and coordination > with TI that would not make sense for small volume projects. Soem things didn't improve over time. I've seen similar setups for the 8032/8052. Here the minimum was 1k units, but this was some 20 years ago. However, there was a version of the 8032 which had a piggy-backed EPROM replacing the mask rom, so you could test the later mass production version with 1:1 pin- and layout. > AFAIK there's no flash that works off 0.9V, even for reading. I think > there needs to be a charge pump of some sort. I think it would work if > the MSP contained an open collector high-voltage transistor and a > diode, feeding an external capacitor that provides 3V supply for the > on-chip flash, temporarily, while it's being transfered to RAM. Add some more transistors and 3 external capacitors and you're done with a voltage doubler with very low losses. 1.8V should be okay for reading. And for programming, you can raise VCC by the FET. Also, low voltage does not necessarily mean low power. There may be many usages where 0.9v (<1.2V = 1 accu cell) are required, but one mA more or less doesn't count. So the device could even run permanently form internal flash. But well, the current versions are as they are. JMGross ------------------------------------------------------------------------------ WhatsUp Gold - Download Free Network Management Software The most intuitive, comprehensive, and cost-effective network management toolset available today. Delivers lowest initial acquisition cost and overall TCO of any competing solution. http://p.sf.net/sfu/whatsupgold-sd _______________________________________________ Mspgcc-users mailing list Mspgcc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mspgcc-users
