Hardware manual

Microcomputer Technical Q&A
113
Q&A No.: QAH8S-234
Category: SCI
Subject: Interrupt Source Flag Clearing
Question
If a receive-error interrupt is generated, and the receive error flags (ORER, FER, PER) in the
serial status register (SSR) are not cleared in the interrupt handling routine before returning to the
main routine, will another receive-error interrupt be generated?
Answer
Yes. As the receive error flags are not cleared to 0 automatically, another receive-error interrupt
will be generated on return to the main routine (on execution of the RTE instruction).
Note: The interrupt will be generated as soon as interrupt masking is released.
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 — — — —