
S1C62N33 TECHNICAL HARDWARE
EPSON
I-103
CHAPTER 5: SUMMARY OF NOTES
Consequently, when the input terminal is in the active
status (low status), do not rewrite the mask register
(clearing, then setting the mask register), so that a factor
flag will only set at the falling edge in this case. When
clearing, then setting the mask register, set the mask
register, when the input terminal is not in the active
status (high status).
When an interrupt is triggered at the rising edge of the
input terminal, a factor flag will be set at the timing of
shown in Figure 5.2.1. In this case, when the mask
registers cleared, then set, you should set the mask
register, when the input terminal is in the low status.
In addition, when the mask register = "1" and the content
of the differential register is rewritten in the input termi-
nal active status, an input interrupt factor flag may be
set. Thus, you should rewrite the content of the differen-
tial register in the mask register = "0" status.
(4) Read-out the interrupt factor flag (IK) only in the DI
status (interrupt flag = "0"). Read-out during EI status
will cause malfunction.
(5) Writing to the interrupt mask registers (EIK) can be done
only in the DI status (interrupt flag = "0"). Writing during
EI status will cause malfunction.
(6) When oscillation is stopped, the reset triggered by the
noise reject circuit which would normally take place
when the input ports are simultaneously switched to
HIGH cannot be received.
When BZ, BZ and FOUT are selected with the mask option,
a hazard may be observed in the output waveform when the
data of the output register changes.
(1) When the I/O port is being read out, the in-built pull-
down resistance of the I/O port goes ON. Consequently, if
data is read out while the CPU is running in the OSC3
oscillation circuit, data must be read out continuously for
about 500 s.
Output port
I/O port