Hardware manual

Microcomputer Technical Q&A
35
Q&A No.: QAH8S-030
Category: Interrupts
Subject: Insufficient Number of External Interrupts
Question
Can any substitution method be used if more external interrupts are needed?
Answer
TPU input capture can be used as a substitute.
An unused TPU timer general register (TGR) is set to input capture. When the designated edge is
input at the TIOC input, the TGR flag is set and an input capture interrupt is generated. This can
be used in the same way as an edge-input IRQ.
16-bit free-running timer (FRT) input capture input can also be used in the same way.
Applicable Products
Applicability Series Applicability Series Applicability Series
Entire H8S Series Yes H8S/2655 Yes H8S/2350
Yes H8S/2355 Yes H8S/2357 Yes H8S/2345
Yes H8S/2245 H8S/2148 H8S/2144
H8S/2138 H8S/2134 H8S/2128
H8S/2124 — — — —