UPD784938 Datasheet, PDF (579/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 23 INTERRUPT FUNCTIONS
23.8.8 Macro service type C
(1) Operation
In type C macro service, data in the memory specified by the macro service channel is transferred to two SFRs, for
timer use and data use, specified by the macro service channel in response to a single interrupt request (the SFRs
can be freely selected). An 8-bit or 16-bit timer SFR can be selected.
In addition to the basic data transfers described above, type C macro service, the following functions can be added
to type C macro service to reduce the size of the buffer area and alleviate the burden on software.
These specifications are made by using the mode register of the macro service control word.
(a) Updating of timer macro service pointer
It is possible to choose whether the timer macro service pointer (MPT) is to be kept as it is or incremented/
decremented. The MPT is incremented or decremented in the same direction as the macro service pointer (MPD)
for data.
(b) Updating of data macro service pointer
It is possible to choose whether the data macro service pointer (MPD) is to be incremented or decremented.
(c) Automatic addition
The current compare register value is added to the data addressed by the timer macro service pointer (MPT), and
the result is transferred to the compare register. If automatic addition is not specified, the data addressed by the
MPT is simply transferred to the compare register.
(d) Ring control
An output data pattern of the length specified beforehand is automatically output repeatedly.
Preliminary User’s Manual U13987EJ1V0UM00
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