r5s72060w200fpv Renesas Electronics Corporation., r5s72060w200fpv Datasheet - Page 1004

• Manufacturer Part Number: r5s72060w200fpv
• Description: 32-bit Risc Microcomputer Superhtm Risc Engine Family / Sh7200 Series
• Manufacturer: Renesas Electronics Corporation.

Section 22 Power-Down Modes
22.2.6
SYSCR2 is an 8-bit readable/writable register that enables or disables write to the on-chip RAM.
SYSCR2 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 valid.
When an RAMWE bit is set to 1, the corresponding on-chip RAM area is enabled. When an
RAMWE bit is cleared to 0, the corresponding on-chip RAM area cannot be written to. In this
case, writing to the on-chip RAM is ignored. The initial value of an RAMWE 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
RAMWE 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 SYSCR2. If an on-chip RAM access
instruction is set, normal access is not guaranteed.
Note: See section 22.4, Usage Notes, when writing data to this register.
Rev. 2.00 Dec. 09, 2005 Page 980 of 1152
REJ09B0191-0200
Bit
7 to 4
3
2
System Control Register 2 (SYSCR2)
Bit Name

RAMWE3
RAMWE2
Initial value:
Initial
Value
All 1
1
1
R/W:
Bit:
R
7
1
-
R/W
R
R/W
R/W
R
6
1
-
Description
Reserved
These bits are always read as 1. The write value
should always be 1.
RAM Write Enable 3 (corresponding RAM addresses:
Page 3 in on-chip RAM*)
0: On-chip RAM write disabled
1: On-chip RAM write enabled
RAM Write Enable 2 (corresponding RAM addresses:
Page 2 in on-chip RAM*)
0: On-chip RAM write disabled
1: On-chip RAM write enabled
R
5
1
-
R
4
1
-
R/W
RAM
WE3
3
1
RAM
WE2
R/W
2
1
RAM
WE1
R/W
1
1
RAM
WE0
R/W
0
1