CHAPTER 3 INSTALLATION
User’s Manual U16556EJ1V0UM
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3.4
Pin Mask Function Settings
3.4.1 NMI interrupt mask setting
By setting switch 1 of the DIP switch (SW1) in the IE-784937-NS-EM1, it is possible to mask the NMI interrupt,
which is the alternate function of the P20 pin.
Table 3-3. DIP Switch Setting for NMI Interrupt Mask
DIP Switch Setting
Status
1 (NMIMSK)
No NMI mask (initial setting)
ON
NMI masked
OFF
Caution
Because the NMI interrupt is the alternate function of the P20 pin, this pin cannot operate
as the P20 pin when the NMI mask status has been set.
3.4.2 Wait (WAIT)/hold (HOLD) mask function
By setting switches 2 to 4 of the DIP switch (SW1) in the IE-784937-NS-EM1, it is possible to mask the wait
(WAIT) and hold (HOLD) alternate functions of the P66 pin in the
µ
PD784938A Subseries.
Table 3-4. DIP Switch Setting for Wait (WAIT)/Hold (HOLD) Mask Function
DIP Switch Setting
Status
2 (WAITMSK)
3 (HOLDMASK)
4 (P66ON)
No mask (initial setting)
OFF
OFF
ON
Hold masked
OFF
ON
OFF
Wait masked
ON
OFF
OFF
Caution
Do not set the DIP switch to settings other than those above.
3.4.3 Wait display function setting
By setting switch 5 of the DIP switch (SW1) in the IE-784937-NS-EM1, it is possible to display the status of
“waiting” with an LED light.
Table 3-5. DIP Switch Setting for Wait Display Function
DIP Switch Setting
Status
5 (WAITLED)
Wait (WAIT) status not displayed
OFF
Wait (WAIT) status displayed (initial setting)
ON
Caution
When pin P66 is used as a port pin, unless the DIP switch is turned OFF the LED may
light up.
