UPD784938 Datasheet, PDF (577/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 23 INTERRUPT FUNCTIONS
(3) Example of use of type B
An example is shown below in which parallel data is input from port 3 in synchronization with an external signal. The
INTP4 external interrupt pin is used for synchronization with the external signal.
Figure 23-27. Parallel Data Input Synchronized with External Interrupts
64 K memory space
Macro service control word,
Macro service channel
(internal RAM)
0A01FH
Buffer Area
0A000H
MSC
0FE6EH
SFRP
MP
00H
20H
−1
03H^{Note Note Low-order 8 bits of port 3 address}
00H
A0H
+1
00H
Channel pointer 6EH
Type B, SFR → memory, 8-bit transfer,
Mode register 18H interrupt request generation when
MSC = 0
Internal bus
INTP4
Edge
INTP4
detection _{Macro service request}
Port 3
P37
P36
P35
P34
P33
P32
P31
P30
Remark Macro service channel addresses in the figure are the values when the LOCATION 0 instruction is executed.
When the LOCATION 0FH instruction is executed, 0F0000H should be added to the values in the figure.
Preliminary User’s Manual U13987EJ1V0UM00
577