UPD78320 Datasheet, PDF (44/88 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCONTROLLER

µPD78320, 78322
4.2 MACRO SERVICE
The macro service function is executed at the interrupt request to carry out data operation and data transfer in hardware
terms between the special function register area and the memory space.
Upon startup of the macro service, the CPU stops program execution temporarily. 1-byte/2-byte data operation, transfer,
etc. are automatically carried out between the special function register (SFR) and the memory. Upon termination of the macro
service, the interrupt request flag is reset to 0 and the CPU restarts program execution. When the CPU carries out the macro
service operations as many as set into the macro service counter (MSC), a vectored interrupt request is generated after
completion.
Figure 4-2. Macro Service Processing Sequence Example
Macro Service Processing
Interrupt Request Generated
ISM×× ← 0
Macro service execution
; Data Transfer, and Realtime
Output Port Control
MSC ← MSC–1
; Macro Service Counter (MSC)
Decrement (by –1)
Yes
No
MSC = 0?
Interrupt request flag ← 0
Vectored Interrupt Request Occurred
Next Instruction Executed
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