HD6417751RBP240V Datasheet, PDF (31/1226 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

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13.3.11 Bus Arbitration 490, 491 Description amended
There are two bus arbitration modes:
master mode, and
slave mode. In master mode the bus is held on a constant
basis, and is released to another device in response to a bus
request. In slave mode the bus is not held on a constant basis;
a bus request is issued each time an external bus cycle occurs,
and the bus is released again at the end of the access.
Master mode and slave mode can be specified by the external
mode pins.
See Appendix C, Mode Pin Settings, for the
external mode pin settings. In master mode and slave mode,
the bus goes to the high-impedance state when not being held.
Instead of a slave mode chip. In the following
description, an external device that issues bus requests is also
referred to as a slave.
…
To prevent incorrect operation of connected devices when the
bus is transferred between master and slave, all bus control
signals are negated before the bus is released. When
mastership of the bus is received, also, bus control signals
begin driving the bus from the negated state. Since signals are
driven to the same value by the master and slave exchanging
the bus, output buffer collisions can be avoided.
Rev.4.00 Oct. 10, 2008 Page xxix of xcviii
REJ09B0370-0400