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Renesas SH7641 User Manual

Page 351

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Section 12 Bus State Controller (BSC)

Rev. 4.00 Sep. 14, 2005 Page 301 of 982

REJ09B0023-0400

Bit Bit

Name

Initial
Value R/W Description

1

0

HW1

HW0

0

0

R/W

R/W

Number of Delay Cycles from

RD, WEn Negation to

Address,

CSn Negation

Specify the number of delay cycles from

RD, WEn

negation to address, and

CSn negation.

00: 0.5 cycles

01: 1.5 cycles

10: 2.5 cycles

11: 3.5 cycles

Burst ROM (Clock Asynchronous):

• CS0WCR

Bit Bit

Name

Initial
Value R/W Description

31 to 21

 All

0

R

Reserved

These bits are always read as 0. The write value
should always be 0.

20

BEN

0

R/W

Burst Enable Specification

Enables or disables 8-burst access for a 16-bit bus
width or 16-burst access for an 8-bit bus width during
16-byte access. If this bit is set to 0, 2-burst access is
performed four times when the bus width is 16 bits and
4-burst access is performed four times when the bus
width is 8 bits. To use a device that does not support
8-burst access or 16-burst access, set this bit to 1.

0: Enables 8-burst access for a 16-bit bus width and

16-burst access for an 8-bit bus width.

1: Disables 8-burst access for a 16-bit bus width and

16-burst access for an 8-bit bus width.

19, 18

 All

0

R

Reserved

These bits are always read as 0. The write value
should always be 0.

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