"Peter L. Peres" wrote:
>
> On Tue, 14 Jan 2003, Doug Hewett wrote:
>
> *>(1)  You may find 4 channels useful when looking at SPI or Microwire:
> *>(a) data in, (b) data out, (c) clock, (d) slave select.
>
> With hawk eyes ;-) I can't see 1MHz signals. Can you ?
>
> Peter

Sure, with a high enough repetition rate it's -easy- to see nanosecond
wide pulses on a GOOD scope. When debugging code/hardware interactions,
you put in the shortest loop you can to see where stuff is 'broken'.

And I would strongly second the recommendation for a 4 channel scope if
debugging
SPI/I2C hardware. It's also useful for 'normal' debugging, where you trigger
the scope with your chip select or address decoder and then confirm that the
/OE, R/W & data lines are doing what they're supposed to.
I often find myself using both channels on TWO stacked TEK 465 scopes to
get my 4 channels (6 if you count the way I use external trigger as a
"channel").

Robert

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