Datasheet
Section 23 Power-Down Modes 
Page 1146 of 1384    R01UH0310EJ0500 Rev. 5.00 
 Sep 25, 2012 
H8S/2426, H8S/2426R, H8S/2424 Group
Bit  Bit Name  Initial Value  R/W  Description 
5  ⎯ 0  ⎯ Reserved 
This bit is always read as 0. The initial value 
should not be changed. 
4  ⎯ 0  ⎯ Reserved 
This bit is always read as 0. The write value 
should always be 0. 
3 
2 
1 
0 
STS3 
STS2 
STS1 
STS0 
1 
1 
1 
1 
R/W 
R/W 
R/W 
R/W 
Standby Timer Select 3 to 0 
These bits select the time the MCU waits for the 
clock to stabilize when software standby mode is 
cleared by an external interrupt. With crystal 
oscillation, see table 23.2 and make a selection 
according to the operating frequency so that the 
standby time is at least the oscillation stabilization 
time. With an external clock, a PLL circuit 
stabilization time is necessary. See table 23.2 to 
set the standby time. When DRAM is used and 
self-refreshing in the software standby state is 
selected, note that the DRAM’s tRAS (self-refresh 
RAS pulse width) specification must be satisfied. 
0000: Setting prohibited 
0001: Setting prohibited 
0010: Setting prohibited 
0011: Setting prohibited 
0100: Setting prohibited 
0101: Standby time = 64 states 
0110: Standby time = 512 states 
0111: Standby time = 1024 states 
1000: Standby time = 2048 states 
1001: Standby time = 4096 states 
1010: Standby time = 16384 states 
1011: Standby time = 32768 states 
1100: Standby time = 65536 states 
1101: Standby time = 131072 states 
1110: Standby time = 262144 states 
1111: Standby time = 524288 states 
Note:  *  Not included in the 5-V version. 










