Renesas SH7264 User Manual

Page of 2152
 
Section 33   Power-Down Modes 
R01UH0134EJ0400  Rev. 4.00  
 
Page 1795 of 2108 
Sep 24, 2014 
 
 
 
SH7262 Group, SH7264 Group 
Bit Bit 
Name 
Initial 
Value R/W Description 
7 to 4 
 All 
Reserved 
These bits are always read as 0. The write value 
should always be 0. 
RRAMWE3  0 
R/W 
RAM Write Enable 3 (corresponding area: page 3*
3
*
4
 
in on-chip data-retention RAM) 
0: Writing to page 3 is disabled. 
1: Writing to page 3 is enabled. 
RRAMWE2  0 
R/W 
RAM Write Enable 2 (corresponding area: page 2*
2
 in 
on-chip data-retention RAM 
0: Writing to page 2 is disabled. 
1: Writing to page 2 is enabled. 
RRAMWE1  0 
R/W 
RAM Write Enable 1 (corresponding area: page 1*
2
 in 
on-chip data-retention RAM 
0: Writing to page 1 is disabled. 
1: Writing to page 1 is enabled. 
RRAMWE0  0 
R/W 
RAM Write Enable 0 (corresponding area: page 0*
2
 in 
on-chip data-retention RAM) 
0: Writing to page 0 is disabled. 
1: Writing to page 0 is enabled. 
Notes:  1.  For addresses in each page, see section 31, On-Chip RAM. 
 
2.  When the VRAME0 bit in SYSCR3 is cleared to 0 (access to page 0 in large-capacity 
on-chip RAM is invalid), the on-chip data-retention RAM cannot be accessed (read and 
written), regardless of the setting of this bit. 
When the VRAMWE0 bit in SYSCR4 is cleared to 0 (writing to page 0 in large-capacity 
on-chip RAM is invalid), the on-chip data-retention RAM cannot be written, regardless 
of the setting of this bit. 
 
3.  When the VRAME1 bit in SYSCR3 is cleared to 0 (access to page 1 in large-capacity 
on-chip RAM is invalid), the first half (page 1 in large-capacity on-chip RAM) of the on-
chip data-retention RAM cannot be accessed (read and written), regardless of the 
setting of this bit. 
When the VRAME1 bit in SYSCR4 is cleared to 0 (writing to page 1 in large-capacity 
on-chip RAM is invalid), the first half of the on-chip data-retention RAM cannot be 
written, regardless of the setting of this bit. 
 
4.  When the VRAME2 bit in SYSCR3 is cleared to 0 (access to page 2 in large-capacity 
on-chip RAM is invalid), the second half (page 2 in large-capacity on-chip RAM) of the 
on-chip data-retention RAM cannot be accessed (read and written), regardless of the 
setting of this bit. 
When the VRAMWE2 bit in SYSCR4 is cleared to 0 (writing to page 2 in large-capacity 
on-chip RAM is invalid), the second half of the on-chip data-retention RAM cannot be 
written, regardless of the setting of this bit.