>> The way I interpret the data sheet (I assume the 823 and 860 are
similar) is that I get the TX
>> interrupt when the I2C address is sent plus the two character
times. The rest of the TX buffer
>> is just a place holder and will not be sent.
>Not correct. The data isn't sent on the data lines, but the CPM
decrements the
>counter and uses it to time the receive transfer. The I2C thinks
it is sending
>something, but the bits just fall off the sand into a bucket. It
is used to generate
>the timing of the clock and count how many receive bytes you wish
to acquire.
According to the MPC823e User's Manual:
"The I2C receiver and transmitter are double-buffered, which corresponds to
an effective
FIFO size of 2 characters. The MPC823e I2C bit 0 (MSB) is shifted out
first." pg. 16-456
I interpret this to account for the additional two character clock times
you'll need to do.
Just my $.02,
Michael Pergola
Software Engineer
Baltimore, MD 21236 (410) 931-6778 x4259
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