R0K572115S000BE Renesas Electronics America, R0K572115S000BE Datasheet - Page 1027

• Manufacturer Part Number: R0K572115S000BE
• Description: KIT STARTER FOR SH7211
• Manufacturer: Renesas Electronics America
• Series: Renesas Starter Kits (RSK)r
• Type: Microcontrollerr

Specifications of R0K572115S000BE

• Contents: CPU Board, LCD Display Module, E8 Emulator, Cable, QuickStart Guide and CD-ROM
• For Use With/related Products: SH7211
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

23.3.5
SYSCR1 is an 8-bit readable/writable register that enables or disables access to the on-chip RAM.
SYSCR1 is initialized to H'FF by a power-on reset but retains its previous value by a manual reset
or in software standby mode. Only byte access is possible.
When an RAME bit is set to 1, the corresponding on-chip RAM area is enabled. When an RAME
bit is cleared to 0, the corresponding on-chip RAM area cannot be accessed. In this case, an
undefined value is returned when reading data or fetching an instruction from the on-chip RAM,
and writing to the on-chip RAM is ignored. The initial value of an RAME bit is 1.
Note that when clearing the RAME bit to 0 to disable the on-chip RAM, be sure to execute an
instruction to read from or write to the same arbitrary address in each page before setting the
RAME bit. If such an instruction is not executed, the data last written to each page may not be
written to the on-chip RAM. Furthermore, an instruction to access the on-chip RAM should not be
located immediately after the instruction to write to SYSCR1. If an on-chip RAM access
instruction is set, normal access is not guaranteed.
To enable the on-chip RAM by setting the RAME bit to 1, place an instruction to read data from
SYSCR1 immediately after an instruction to write to SYSCR1. If an instruction to access the on-
chip RAM is placed immediately after the instruction to write to SYSCR1, normal access is not
guaranteed.
Bit
7 to 4
3
System Control Register 1 (SYSCR1)
Bit Name
⎯
RAME3
Initial value:
Initial
Value
All 1
1
R/W:
Bit:
R
7
1
-
R/W
R
R/W
R
6
1
-
Description
Reserved
These bits are always read as 1. The write value
should always be 1.
RAM Enable 3 (corresponding RAM addresses:
H'FFF86000 to H'FFF87FFF)
0: On-chip RAM disabled
1: On-chip RAM enabled
Note: This is a reserved bit on versions with 24 KB of
R
5
1
-
R
4
1
-
RAM. Its value is always 1 when read. Always
write 1 to this bit.
RAME3 RAME2 RAME1 RAME0
R/W
3
1
Rev. 3.00 Mar. 04, 2009 Page 1001 of 1168
R/W
2
1
R/W
1
1
R/W
0
1
REJ09B0344-0300