UPD784938 Datasheet, PDF (592/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 23 INTERRUPT FUNCTIONS
23.8.9 Counter mode
(1) Operation
MSC is decremented the number of times set in advance to the macro service counter (MSC).
Because the number of times an interrupt occurs can be counted, this function can be used as an event counter where
the interrupt generation cycle is long.
Figure 23-39. Macro Service Data Transfer Processing Flow (counter mode)
Macro service request
acknowledged
Reads contents of macro service
mode register
Identifies channel type
Others
To other macro service processing
Counter mode
MSC MSC-1
MSC is 16 bits wide
MSC = 0?
No
Yes
Clears interrupt processing type
bit (ISM) to 0
VCIE = 1?
No
Yes
Clears interrupt request flag
(IF) to 0
End
End
(Vectored interrupt request is generated)
592
Preliminary User’s Manual U13987EJ1V0UM00