Specifications

S1C62N82 TECHNICAL HARDWARE EPSON I-31
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Input Ports)
The contents that can be selected with the input port mask
option are as follows:
(1)An internal pull-down resistance can be selected for each
of the five bits of the input ports (K00–K03, K10). Having
selected "Not Use" (pull-down resistance disabled), take
care that the input does not float. Select "Use" (pull-
down resistance enabled) for input ports that are not
being used.
(2)The input interrupt circuit contains a noise rejector to
prevent interrupts from occurring through noise.
Whether or not to use this noise rejector may be selected
for K00–K03 or K10. When "Use" is selected, a maximum
delay of 0.5 ms (fosc1 = 32 kHz) occurs from the time an
interrupt condition is established until the interrupt
factor flag (IK) is set to 1.
Mask option
In addition, when the mask register = 1 and the content
of the input comparison register is rewritten in the input
terminal active status, an input interrupt factor flag may
be set. Thus, you should rewrite the content of the input
comparison register in the mask register = 0 status.