Hardware manual

Microcomputer Technical Q&A
103
Q&A No.: QAH8S-228
Category: SCI
Subject: Maximum External Clock Input Value (Asynchronous Mode)
Question
What is the maximum possible external clock input frequency in asynchronous mode?
Answer
The cycle of the external clock input to the SCI must be at least 4 × t
cyc
(min.). With a 20 MHz
operating frequency, the maximum value for external clock input is 5 MHz (max.).
Applicable Products
Applicability Series Applicability Series Applicability Series
Yes Entire H8S Series H8S/2655 H8S/2350
H8S/2355 H8S/2357 H8S/2345
H8S/2245 H8S/2148 H8S/2144
H8S/2138 H8S/2134 H8S/2128
H8S/2124 — — — —