Manualshelf

Hardware manual

ManualsBrandsRenesas ManualsComputer HardwareH8S/2138 Series
919293949596979899100
Microcomputer Technical Q&A
86
Q&A No.: QAH8S-212
Category: DMAC
Subject: DREQ Signal Input
Question
When the DREQ pin is used in level-sensing mode, must it be held low until the data transfer
ends?
Answer
The DREQ signal is latched at the rise of
φ
, and once latched the activation source is held. The
activation source will therefore be held if the DREQ pin remains low for at least two states.
Applicable Products
Applicability Series Applicability Series Applicability Series
Entire H8S Series Yes H8S/2655 Yes H8S/2350
H8S/2355 Yes H8S/2357 H8S/2345
H8S/2245 H8S/2148 H8S/2144
H8S/2138 H8S/2134 H8S/2128
H8S/2124 — — — —