R0K572030S000BE Renesas Electronics America, R0K572030S000BE Datasheet - Page 383

Manufacturer Part Number

R0K572030S000BE

KIT DEV FOR SH7203

Manufacturer

Renesas Electronics America

Renesas Starter Kits (RSK)r

CPU Board, LCD Module, E10A-Lite Emulator, Cable, QuickStart Guide and CD-ROM

Silicon Manufacturer

Kit Contents

Silicon Family Name

Silicon Core Number

R5S72030W200FP

Tool / Board Applications

General Purpose MCU, MPU, DSP, DSC

Mcu Supported Families

Lead Free Status / RoHS Status

Contains lead / RoHS non-compliant

For Use With/related Products

Lead Free Status / Rohs Status

Section 9 Bus State Controller (BSC)

Relationship between Refresh Requests and Bus Cycles

If a refresh request occurs during bus cycle execution, the refresh cycle must wait for the bus cycle

to be completed. If a refresh request occurs while the bus is released by the bus arbitration

function, the refresh will not be executed until the bus mastership is acquired. This LSI has the

REFOUT pin to request the bus while waiting for refresh execution. For REFOUT pin function

selection, see section 25, Pin Function Controller (PFC). This LSI continues to assert REFOUT

(low level) until the bus is acquired.

On receiving the asserted REFOUT signal, the external device must negate the BREQ signal and

return the bus. If the external bus does not return the bus for a period longer than the specified

refresh interval, refresh cannot be executed and the SDRAM contents may be lost.

If a new refresh request occurs while waiting for the previous refresh request, the previous refresh

request is deleted. To refresh correctly, a bus cycle longer than the refresh interval or the bus

mastership occupation must be prevented from occurring.

If a bus mastership is requested during self-refresh, the bus will not be released until the refresh is

Rev. 3.00 Sep. 28, 2009 Page 351 of 1650

REJ09B0313-0300