Hitachi H8S/2378, H8S/2378R Series Hardware Manual page 177

Bit Bit Name
−
11
10 RTCK2
9 RTCK1
8 RTCK0
7 RFSHE
6 CBRM
Initial Value R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
Description
Reserved
This bit is always read as 0. The initial value
should not be changed.
Refresh Counter Clock Select
These bits select the clock to be used to
increment the refresh counter. When the input
clock is selected with bits RTCK2 to RTCK0, the
refresh counter begins counting up.
000: Count operation halted
001: Count on ø/2
010: Count on ø/8
011: Count on ø/32
100: Count on ø/128
101: Count on ø/512
110: Count on ø/2048
111: Count on ø/4096
Refresh Control
Refresh control can be performed. When
refresh control is not performed, the refresh
timer can be used as an interval timer.
0: Refresh control is not performed
1: Refresh control is performed
CBR Refresh Control
Selects CBR refreshing performed in parallel
with other external accesses, or execution of
CBR refreshing alone.
When the continuous synchronous DRAM
space is set, this bit can be read/written, but the
setting contents do not affect operations.
0: External access during CAS-before-RAS
refreshing is enabled
1: External access during CAS-before-RAS
refreshing is disabled
Rev. 1.0, 09/01, page 133 of 904