[Coco] deuce memory bandwidth?

KnudsenMJ at aol.com KnudsenMJ at aol.com
Sat Aug 7 22:36:34 EDT 2004


In a message dated 8/7/04 2:38:59 PM Eastern Daylight Time, jdaggett at gate.net 
writes:

> The 6809 chip itself has its own crystal oscillator and phase 
>  generator inside. The crystal itself must run at 4 times the buss 
>  frequency.

Correct, but just to be clear -- the user must supply the crystal externally, 
and connect it to a couple of pins (one of which is the external clock input 
in the 6809E, which lacks the oscillator circuitry).

After the discussion of the Smart Watch chip with the lithium battery built 
in, I didn't want anyone to think that some 6809 had a built-in crystal.

Of course, there have been many little tin-can modules with their own 
crystals inside, such as complete Touch-Tone dial receivers, but not the 6809.  In 
fact, the Smart Watch and cousins have a watch crystal built in.  --Mike K.



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