[Coco] Hitachi HD63C09 Question

[Mark Marlette]

james,

Depending on the specfics of what you are trying to do. It depends.

Most of the CPLDs/AVRs that we are now using at Cloud-9 are 3.3vdc.

Most are 5v tolerant I/O and depending on what family you are  
interfacing to requires you do either to pullup and have OC/OD outputs  
or nothing at all. Generally a white paper by the manufacture.

Not sure on the Hitachi, that is on the 5vdc side of our designs.

Good luck on your project.

Regards,

Mark
Cloud-9

Quoting jdaggett at gate.net:

> On 20 Jun 2007 at 22:00, George's Coco Address wrote:
>
>> Since you've asked this before and no one has replied, I would assume
>> that no one has tried it, or won't admit to it. It is an interesting
>> query.
>>
> **************
>
> KInd of why I am asking is I am working on a project that has a lot   
> of 3.3V logic. If
> the processor would run at that voltage then it would simplify   
> interfacing the
> processor to the rest of the circuit. I was just wondering if anyone  
>  had tried before
> I did.
>
> james
>> ----- Original Message -----
>> From: <jdaggett at gate.net>
>> To: "coCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>> Sent: Wednesday, June 20, 2007 8:41 PM Subject: [Coco] Hitachi HD63C09
>> Question
>>
>>
>> >I know the Coco Community has used the Hitachi 6309 chip for a while.
>> >Most
>> > operation has centered around speeding up the 63C09E be yond 3MHz. I
>> > was wondering if anyone has experimented running the MPU at or below
>> > 2MHz and at 3.3VDC instead of 5VDC? IF the 63C09 was designed in the
>> > mid 80's then it is possible that at normal speeds the 63C09E just
>> > might run at 3.3VDC.
>> >
>> > Has anyone attempted or does anyone know of any tests done with
>> > lower VDC?
>> >
>> > james
>> >
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