Ram Registers - Micro crystal RV-1805-C3 Applications Manual

Micro Crystal
Extrem Low Power Real Time Clock / Calendar Module
2Eh – ID6 – Wafer (Read Only)
Address Function
ID6 – Wafer (Read Only)
2Eh
Reset
Bit Symbol
7 Lot[8]
6:1 Wafer
1:0 RESERVED
3.12.

RAM REGISTERS

3Fh - Extension RAM Address
This register controls access to the Extension RAM, and includes some miscellaneous control bits.
Address Function
Extension RAM Address
3Fh
Reset
Bit Symbol
7 X
6 BPOL
5 WDIS
4 X
3 RESERVED
2 XADA
1:0 XADS
Bit 7 Bit 6 Bit 5
Lot[8]
Value
0 or 1 This field holds bit 8 of the manufacturing lot number.
00000
to This field holds the manufacturing wafer number.
11111
00 to 11 RESERVED
Bit 7 Bit 6 Bit 5
X BPOL WDIS
0 0 Read Only
Value
Unused, but must be set to 0 to avoid extraneous leakage. If 0, an internal
0 output is completely disconnected when the RV-1805-C3 is powered from
V .
BACKUP
The Battery Low flag BLF is set when the V
0
BREF threshold.
The Battery Low flag BLF is set when the V
1
BREF threshold.
(read only) – WDI status. Currently low level on the WDI pin.
0
(read only) – WDI status. Currently high level on the WDI pin.
1
(read only) – Unused
0
0 or 1 RESERVED
0 or 1 This bit supplies the upper bit for the Alternate RAM address space.
00 to 11 This field supplies the two upper bits for the Standard RAM address space.
Bit 4 Bit 3 Bit 2
Wafer
Preconfigured Value
Description
Bit 4 Bit 3 Bit 2
X XADA
RESERVED
0 0
Description
BLF Polarity
voltage goes below the
BACKUP
voltage goes above the
BACKUP
RV-1805-C3
Bit 1 Bit 0
RESERVED
Bit 1 Bit 0
XADS
0 0
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