Panasonic MN101C77C - Manual (Page 459)

Operation
Chapter 14 Automatic Transfer Controller
XIV - 21
13
To execute a continuous serial transaction, you must pre-store the serial transmission data in
the memory space that memory pointer 0 points, the transmission data must fill every other
address in the space. Once the serial transaction ends, the received data is stored empty
(skipped) addresses and the transmission and reception data at stored in an alternating
pattern.
In transfer mode 6, ATC1 executes a data byte transfer twice each time it is activated. The value in
memory pointer 0 increments by one each time a byte-length data transfer ends. As a result, the source
address for the next ATC1 operation is two addresses higher than that for the previous operation.
Set the data transfer count for ATC1 in the transfer data counter (AT1TRC). The counter can be set to a
maximum of 255 transfers. The counter decrements each time ATC1 is activated (after one byte of data
has been transferred twice). When it reaches x'00', an interrupt (ATC1IRQ) occurs and the automatic
transfer ends.