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3 access wait control – Renesas SH7641 User Manual

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Section 12 Bus State Controller (BSC)

Rev. 4.00 Sep. 14, 2005 Page 329 of 982

REJ09B0023-0400

12.5.3

Access Wait Control

Wait cycle insertion on a normal space access can be controlled by the settings of bits WR3 to
WR0 in CSnWCR. It is possible for areas 4, 5A, and 5B to insert wait cycles independently in
read access and in write access. The areas other than 4, 5A, and 5B have common access wait for
read cycle and write cycle. The specified number of Tw cycles are inserted as wait cycles in a
normal space access shown in figure 12.9.

T1

CKIO

A25 to A0

CSn

RD/

WR

RD

D31 to D0

WEn

D31 to D0

BS

Tw

Read

Write

T2

DACKn*

Note: * The waveform for

DACKn is when active low is specified.

Figure 12.9 Wait Timing for Normal Space Access (Software Wait Only)

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