Specifications

II-90 EPSON S1C62N82 TECHNICAL SOFTWARE
CHAPTER 4: SUMMARY OF PROGRAMMING POINTS
– When switching the clock from OSC3 to OSC1, use a
separate instruction for switching the OSC3 oscillation
OFF.
– To lessen current consumption, keep OSC3 oscillation
OFF except when the CPU must be run at high speed.
Also, with S1C62N82/62L82, keep OSCC fixed to "0".
• Input Port – When modifying the input port from high level to low level
with pull-down resistance, a delay will occur at the rise of
the waveform due to time constant of the pull-down
resistance and input gate capacities. Provide appropriate
waiting time in the program when performing input port
reading.
– Input interrupt programing related precautions
When the content of the mask register is rewritten, while the port K
input is in the active status. The input interrupt factor flags are set at
➀ and ➁, ➀ being the interrupt due to the falling edge and ➁ the
interrupt due to the rising edge.
Fig. 4.1
Input interrupt timing
When using an input interrupt, if you rewrite the content
of the mask register, when the value of the input terminal
which becomes the interrupt input is in the active status,
the factor flag for input interrupt may be set. Therefore,
when using the input interrupt, the active status of the
input terminal implies
input terminal = Low status, when the falling edge
interrupt is effected and
input terminal = High status, when the rising edge
interrupt is effected.
When an interrupt is triggered at the falling edge of an
input terminal, a factor flag is set with the timing of ➀
shown in Figure 4.1.
Port K input
Factor flag set Not set ➁ Factor flag set
Input comparison
register
Mask register
Active status
Active status
Rising edge interrupt
➀
Falling edge interrupt