Renesas R5S72621 Doll User Manual


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Section 33 Power-Down Modes
Page 1790 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
Bit Bit Name
Initial
Value R/W Description
1 RAME1 1 R/W RAM Enable 1 (corresponding area: page 1* in high-
speed on-chip RAM)
0: Access to page 1 is disabled.
1: Access to page 1 is enabled.
0 RAME0 1 R/W RAM Enable 0 (corresponding area: page 0* in high-
speed on-chip RAM)
0: Access to page 0 is disabled.
1: Access to page 0 is enabled.
Note: * For addresses in each page, see section 31, On-Chip RAM.
33.2.11 System Control Register 2 (SYSCR2)
SYSCR2 is an 8-bit readable/writable register that enables or disables writing to a specified page
in the high-speed on-chip RAM.
When an RAMEn (n = 0 to 3) bit is set to 1, writing to page n is enabled. When an RAMEn bit is
cleared to 0,writing to page n is ignored. The initial value of an RAMEn bit is 1.
Note that when clearing the RAMWEn bit to 0, be sure to execute an instruction to read from or
write to the same arbitrary address in each page before setting the RAMWEn bit. If such an
instruction is not executed, the data last written to page n may not be written to the high-speed on-
chip RAM.
SYSCR2 should be set with a program located in an area other than the high-speed on-chip RAM. Furthermore, an
instruction to read SYSCR2 should be located immediately after the instruction to write to SYSCR2. If not, normal access
is not guaranteed.
Note: When writing to this register, see section 33.4, Usage Notes.
76543210
Bit:
Initial value:
R/W:
11111111
R R R R R/W R/W R/W R/W
----
RAM
WE3
RAM
WE2
RAM
WE0
RAM
WE1