Motorola M68EM05P18, User Manual

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MMDS/MMEVS Configuration and Operation
Setting M68EM05P18 Jumper
M68EM05P18UM/D
24 MMDS/MMEVS Configuration and Operation MOTOROLA
Port A Interrupt
Mask Option
Control Switch,
SW1 The eight positions of switch SW1 enable or disable the port A interrupt
mask options. Each position controls one port A line. A switch in the left
position, OFF, disables the option; a switch in the right position, ON,
enables the option.
If a mask option is enabled (switched ON) and the corresponding bit of
the port A data direction register is configured as an input, a low on the
port A pin generates an interrupt. The diagram here shows a possible
setting: Interrupt masks are disabled for port A lines 0 through 3 and are
enabled for port A lines 4 through 7.
The default setting for all eight positions of SW1 is OFF.
PA0
PA7
ON
PORT A MASK
OPTION PULLUPS
SW1