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Hi everyone! I've been working on an Adapt9s12e128 development board for the last month with this project and now i'm moving into creating a prototype board of my own. I've gotten started but i'm a little confused on the different VDD1/VDD2/VDDPLL voltage supply pins. The device user guide mentions that they are all 2.5V pins, but also says that the 2.5 voltage is generated by an internal voltage regulator. So does this mean i supply the pin with 5V? Another thing i came across was the load/run switch which got me thinking. I assume that chips comming straight from the manafactures will not have the debug code loaded in. Will that mean that programming can not be done through the serial (SCI0) port, rather only through a BDM module/cable? Any extra tips on creating a HCS12 prototype board would be great as this is my first PCB with more than some LEDs and simple logic. Thanks

Re: HCS12 prototype
Re: HCS12 prototype


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I think the docs are very short on sample/example circuits. The Vdd1/Vdd2 pins should be connected to caps, it is possible to drive the core with 2.5v applied to these pins but not recommended, AFAIK. VddPLL is also connected to a cap and is used as the return path for the PLL loop filter components connected to XFC. And yes the chips are blank and you will need a BDM interface. There is "talk" of some chips being manufactured with a bootloader, but this has not happened yet(?). I have a few odd PCBs, from old jobs. If one suits you, I can post it to you. Email me off list if this is of use. Good luck. Peter L. At 04:45 AM 1/02/2005 +0000, you wrote: >Hi everyone! > >I've been working on an Adapt9s12e128 development board for the last >month with this project and now i'm moving into creating a prototype >board of my own. I've gotten started but i'm a little confused on >the different VDD1/VDD2/VDDPLL voltage supply pins. The device user >guide mentions that they are all 2.5V pins, but also says that the >2.5 voltage is generated by an internal voltage regulator. So does >this mean i supply the pin with 5V? > >Another thing i came across was the load/run switch which got me >thinking. I assume that chips comming straight from the >manafactures will not have the debug code loaded in. Will that mean >that programming can not be done through the serial (SCI0) port, >rather only through a BDM module/cable? > >Any extra tips on creating a HCS12 prototype board would be great as >this is my first PCB with more than some LEDs and simple logic. > >Thanks > >Yahoo! Groups Links

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Ciao the S12 people, 1) basically the 9S12 family has the internal voltage regulator, since the core + osc runs at 2.5V voltage level. So there are two possible scenario: a) use the internal voltage regulator (recommended), then the VDD1+VDD2+VDDPLL are the outputs from the internal voltage regulator (2.5V) and you have (not should) to connect recommended decouple capacitors (the values can be found at "device user guide" document for every derivative of the 9S12 family in section "voltage regulator"). The second scenario is "not to used" the internal voltage regulator (VREGEN pin enable/disable the internal voltage regulator, pin is available only on some derivatives of the 9S12 family!) - then you must supply the pins VDD1, VDD2, VDDPLL by external power supply 2.5V. 2) the silicons from the factory come blank, so you have to use standard BDM pod to program it. There was plan to pre-programmed some kind of bootloader into some derivatives of the 9S12 family but currently this is not done - so devices are blank. Also remember that every "bootloader" has some kind of limitations(usually COP, blocked one SCI channel, interrupts latency etc.), which the BDM pod overcomes! Jasa --- In , "the_oog6789" <oog25@h...> wrote: > > Hi everyone! > > I've been working on an Adapt9s12e128 development board for the last > month with this project and now i'm moving into creating a prototype > board of my own. I've gotten started but i'm a little confused on > the different VDD1/VDD2/VDDPLL voltage supply pins. The device user > guide mentions that they are all 2.5V pins, but also says that the > 2.5 voltage is generated by an internal voltage regulator. So does > this mean i supply the pin with 5V? > > Another thing i came across was the load/run switch which got me > thinking. I assume that chips comming straight from the > manafactures will not have the debug code loaded in. Will that mean > that programming can not be done through the serial (SCI0) port, > rather only through a BDM module/cable? > > Any extra tips on creating a HCS12 prototype board would be great as > this is my first PCB with more than some LEDs and simple logic. > > Thanks

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