R0K572030S000BE Renesas Electronics America, R0K572030S000BE Datasheet - Page 412

• 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)
9.5.12
As the operating frequency of LSIs becomes higher, the off-operation of the data buffer often
collides with the next data access when the read operation from devices with slow access speed is
completed. As a result of these collisions, the reliability of the device is low and malfunctions may
occur. A function that avoids data collisions by inserting idle (wait) cycles between continuous
access cycles has been newly added.
The number of wait cycles between access cycles can be set by the WM bit in CSnWCR, bits
IWW2 to IWW0, IWRWD2 to IWRWD0, IWRWS2 to IWRWS0, IWRRD2 to IWRRD0, and
IWRRS2 to IWRRS 0 in CSnBCR, and bits DMAIW2 to DMAIW0 and DMAIWA in CMNCR.
The conditions for setting the idle cycles between access cycles are shown below.
1. Continuous access cycles are write-read or write-write
2. Continuous access cycles are read-write for different spaces
3. Continuous access cycles are read-write for the same space
4. Continuous access cycles are read-read for different spaces
5. Continuous access cycles are read-read for the same space
6. Data output from an external device caused by DMA single address transfer is followed by
7. Data output from an external device caused by DMA single address transfer is followed by any
For the specification of the number of idle cycles between access cycles described above, refer to
the description of each register.
Besides the idle cycles between access cycles specified by the registers, idle cycles must be
inserted to interface with the internal bus or to obtain the minimum pulse width for a multiplexed
pin (WEn). The following gives detailed information about the idle cycles and describes how to
estimate the number of idle cycles.
The number of idle cycles on the external bus from CSn negation to CSn or CSm assertion is
described below. Here, CSn and CSm also include CE2A and CE2B for PCMCIA.
There are eight conditions that determine the number of idle cycles on the external bus as shown
in table 9.21. The effects of these conditions are shown in figure 9.53.
Rev. 3.00 Sep. 28, 2009 Page 380 of 1650
REJ09B0313-0300
data output from another device that includes this LSI (DMAIWA = 0)
type of access (DMAIWA = 1)
Wait between Access Cycles