R0K572030S000BE Renesas Electronics America, R0K572030S000BE Datasheet - Page 369

• Manufacturer Part Number: R0K572030S000BE
• Description: KIT DEV FOR SH7203
• Manufacturer: Renesas Electronics America
• Series: Renesas Starter Kits (RSK)r
• Type: MCUr

Specifications of R0K572030S000BE

• Contents: CPU Board, LCD Module, E10A-Lite Emulator, Cable, QuickStart Guide and CD-ROM
• Silicon Manufacturer: Renesas
• Kit Contents: Board
• Silicon Family Name: SH7203
• Silicon Core Number: R5S72030W200FP
• Tool / Board Applications: General Purpose MCU, MPU, DSP, DSC
• Mcu Supported Families: SH7203
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: SH7203
• Lead Free Status / Rohs Status: Compliant

Section 9 Bus State Controller (BSC)
(5)
Burst Write
A burst write occurs in the following cases in this LSI.
• Access size in writing is larger than data bus width.
• Write-back of the cache
• 16-byte transfer in DMAC
This LSI always accesses SDRAM with burst length 1. For example, write access of burst length 1
is performed continuously 4 times to write 16-byte continuous data to the SDRAM that is
connected to a 32-bit data bus. This access is called burst write with the burst number 4. The
relationship between the access size and the number of bursts is shown in table 9.17. Figure 9.20
shows a timing chart for burst writes. In burst write, an ACTV command is output in the Tr cycle,
the WRIT command is issued in the Tc1, Tc2, and Tc3 cycles, and the WRITA command is issued
to execute an auto-precharge in the Tc4 cycle. In the write cycle, the write data is output
simultaneously with the write command. After the write command with the auto-precharge is
output, the Trw1 cycle that waits for the auto-precharge initiation is followed by the Tap cycle that
waits for completion of the auto-precharge induced by the WRITA command in the SDRAM.
Between the Trwl and the Tap cycle, a new command will not be issued to the same bank.
However, access to another CS space or another bank in the same SDRAM space is enabled. The
number of Trw1 cycles is specified by the TRWL1 and TRWL0 bits in CS3WCR. The number of
Tap cycles is specified by the WTRP1 and WTRP0 bits in CS3WCR.
Rev. 3.00 Sep. 28, 2009 Page 337 of 1650
REJ09B0313-0300