H8SX1663 datasheet(254/1158 Pages) RENESAS

No. de pieza	H8SX1663

Descripción Electrónicos	Renesas 32-Bit CISC Microcomputer H8SX Family / H8SX/1600 Series

PDF	1158 Pages

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Fabricante Electrónico	RENESAS [Renesas Technology Corp]

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Section 6 Bus Controller (BSC)

Rev.1.00 Jun. 07, 2006 Page 202 of 1102

REJ09B0294-0100

6.6.6

Extension of Chip Select (

CS) Assertion Period

Some external I/O devices require a setup time and hold time between address and

CS signals and

strobe signals such as

RD, LHWR, and LLWR.

Settings can be made in CSACR to insert cycles in which only the

CS, AS, and address signals are

asserted before and after a basic bus space access cycle. Extension of the

CS assertion period can

be set in area units. With the

CS assertion extension period in write access, the data setup and hold

times are less stringent since the write data is output to the data bus.

Figure 6.23 shows an example of the timing when the

CS assertion period is extended in basic bus

3-state access space.

Both extension cycle Th inserted before the basic bus cycle and extension cycle Tt inserted after

the basic bus cycle, or only one of these, can be specified for individual areas. Insertion or non-

insertion can be specified for the Th cycle with the upper eight bits (CSXH7 to CSXH0) in

CSACR, and for the Tt cycle with the lower eight bits (CSXT7 to CSXT0).

H8SX1663 Datasheet(PDF) 254 Page - Renesas Technology Corp