DS2781
PARAMETER EEPROM
Model data for the cells, as well as application operating parameters are stored in the Parameter EEPROM
memory (block 1, addresses 60h–7Fh). The ACR (MSB and LSB) and AS registers are automatically saved to
EEPROM when the RARC result crosses 4% boundaries. This allows the DS2781 to be located outside the
protection FETs. In this manner, if a protection device is triggered, the DS2781 cannot lose more that 4% of charge
or discharge data.
Table 2. Memory Map
ADDRESS (HEX)
DESCRIPTION
READ/WRITE
00
01
Reserved
R
STATUS - Status Register
R/W
02
03
RAAC - Remaining Active Absolute Capacity MSB
RAAC - Remaining Active Absolute Capacity LSB
RSAC - Remaining Standby Absolute Capacity MSB
RSAC - Remaining Standby Absolute Capacity LSB
RARC - Remaining Active Relative Capacity
RSRC - Remaining Standby Relative Capacity
IAVG - Average Current Register MSB
IAVG - Average Current Register LSB
TEMP - Temperature Register MSB
TEMP - Temperature Register LSB
VOLT - Voltage Register MSB
VOLT - Voltage Register LSB
R
R
04
R
05
R
06
R
07
R
08
R
09
R
0A
R
0B
R
0C
R
0D
R
0E
CURRENT - Current Register MSB
CURRENT - Current Register LSB
ACR - Accumulated Current Register MSB
ACR - Accumulated Current Register LSB
ACRL – Low Accumulated Current Register MSB
ACRL – Low Accumulated Current Register LSB
AS - Age Scalar
R
0F
R
10
R/W*
R/W *
R
11
12
13
R
14
R/W *
R/W
R
15
SFR - Special Feature Register
FULL - Full Capacity MSB
16
17
FULL - Full Capacity LSB
R
18
AE - Active Empty MSB
R
19
AE - Active Empty LSB
R
1A
SE - Standby Empty MSB
R
1B
SE - Standby Empty LSB
R
1C to 1E
1F
Reserved
—
R/W
R/W
—
R/W
—
R
EEPROM - EEPROM Register
User EEPROM, Lockable, Block 0
Reserved
20 to 2F
30 to 5F
60 to 7F
80 to AF
B0 to B1
B2 to FF
Parameter EEPROM, Lockable, Block 1
Reserved
FSGAIN – Factory Gain Calibration Value
Reserved
—
*Register value is automatically saved to EEPROM during ACTIVE mode operation and recalled from EEPROM on power-up.
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
