Epson RX8130CE - Related Register of Battery Backup Switchover Function

15 Battery backup switchover function
RX8130CE Jump to Top / Bottom
ETM50E-07 Seiko Epson Corporation 40
15.5. Related register of Battery backup switchover function
Addressh
Function
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
1D
Flag Register
VBLF
0
UF
TF
AF
RSF
VLF
VBFF
1F
Control Register1
SMP
TSEL1
SMP
TSEL0
CHG
EN
INIEN
0
RS
VSEL
BF
VSEL1
BF
VSEL0
1) CHGEN bit
This bit has to be set to allow charging of a Re-chargeable battery connected to V
BAT
from V
DD
pin.
Table 34 CHGEN bit
CHGEN
Data
Description
Write / Read
0
For non-re-chargeable battery use (default setting).
During V
DD
drive SW2 is OFF, battery charging is not available.
1
SW1, SW2 automatic controlled. For re-chargeable battery use
In case of re-chargeable battery use, INIEN should be set to 1 to enable SW1, SW2 automatic control.
To stop battery charging CHGEN should be reset to 0.
.
2) INIEN bit
Note1: When INIEN is used with 0, it must be set up "INIEN=1" before the setting once at least.
When INIEN-bit is used with 0 from just Power-On-Reset value all the time, there is the case that
INIEN=0 mode is incorrect working. For example, Power switching doesn't work.
Therefore, that an INIEN bit is set to 1 in initial setting is recommended.
See "initial setting example".
Note2: when INIEN set to 1 from 0 in V
DD
<V
DET
1, I
2
C is disabled immediately.
Therefore while V
DD
<V
DET
1, I
2
C can't cleared INIEN to 0.
Table 35 INIEN bit
INIEN
Data
Description
Write / Read
0
After INIEN=1, I
2
C and FOUT function is available regardless of V
DET
1 detection.
Power-switching is available.
CHGEN-bit function is disabled. It same as CHGEN = 0.
be careful not to input intermediate voltage to the I
2
C interface.
1
I
2
C, FOUT function is not available while V
DD
< V
DET
1.
I
2
C, FOUT function is available while V
DD
> V
DET
1.
CHGEN bit function is enabled.
Figure 29 Non re-chargeable battery SW1, SW2 control (INIEN:1, CHGEN:0)
Figure 30 Non Re-chargeable battery SW1, SW2 control (INIEN = 1, CHGEN = 0)