Technical information
8.5 Hardware descriptions
SIMATIC IPC477E
154
Operating Instructions, 11/2020, A5E37455003-AF
8.5.4.5
Battery status register (read-only, address 404Dh)
To monitor the status of the CMOS battery, the battery monitoring must be switched on via a
special GPIO register.
The status of the CMOS battery (two-tier) can be read out via the battery status register.
Meaning of the bits
Battery status register (read-only, address 404Dh)
Bit
Meaning
7
6
5
4
3
2
1
0
0 0
CMOS battery capacity is still sufficient.
0 1
CMOS battery capacity is exhausted (remaining capacity is suffi-
cient for approx. one month)
1 1
CMOS battery is empty
8.5.4.6
NVRAM address register
NVRAM occupies a 512 KB memory address area that can be read via PCI registers.
Meaning of the bits
NVRAM address register
PCI register address:
NVRAM base address register
PCI register content:
NVRAM memory address (default)
Length of the memory area
E300 0000
Address is assigned dynamically
(depending on device configura-
tion)
80000 h
