SH7721 datasheet(341/1524 Pages) RENESAS

341 / 1524 page

Section 9

Bus State Controller (BSC)

Rev. 3.00 Jan. 18, 2008 Page 279 of 1458

REJ09B0033-0300

Section 9

Bus State Controller (BSC)

The bus state controller (BSC) outputs control signals for various types of memory that is

connected to the external address space and external devices. The BSC functions enable this LSI

to connect directly with SRAM, SDRAM, and other memory storage devices, and external

devices.

9.1

Features

The BSC has the following features:

(1) External address space

• A maximum 32 or 64 Mbytes for each of the eight areas, CS0, CS2 to CS4, CS5A, CS5B,

CS6A and CS6B, totally 384 Mbytes (divided into eight areas).

• A maximum 64 Mbytes for each of the six areas, CS0, CS2 to CS4, CS5, and CS6, totally a

total of 384 Mbytes (divided into six areas).

• Can specify the normal space interface, byte-selection SRAM, burst ROM (clock synchronous

or asynchronous), SDRAM, PCMCIA for each address space.

• Can select the data bus width (8, 16, or 32 bits) for each address space.

• Controls the insertion of the wait state for each address space.

• Controls the insertion of the wait state for each read access and write access.

• Can set the independent idling cycle in the continuous access for five cases: read-write (in

same space/different space), read-read (in same space/different space), or the first cycle is a

write access.

(2) Normal space interface

• Supports the interface that can directly connect to the SRAM.

(3) Burst ROM (clock asynchronous) interface

• High-speed access to the ROM that has the page mode function.

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