ds2438zt-r Maxim Integrated Products, Inc., ds2438zt-r Datasheet - Page 16

• Manufacturer Part Number: ds2438zt-r
• Description: Ds2438 Smart Battery Monitor
• Manufacturer: Maxim Integrated Products, Inc.

Page 1 (01h)
The second page, Page 1, contains the ICA, elasped time meter, and current offset data. Both the ETM
and ICA are volatile read/write locations so that they may be set, changed, or cleared by the host
software. Bytes 0-3 contain the ETM data, formatted as described in the “Operation - Elapsed Time
Meter” section. Byte 4 contains the 8-bit ICA. Bytes 5 and 6 contain the Offset Register data. Byte 7 is
reserved and will read out as all “1”s.
Page 2 (02h)
The third page of memory (Page 2) contains the Disconnect (first 4 bytes) and End of Charge (remaining
4 bytes) timestamps. This page is volatile and read/write. Refer to the “Operation – Elapsed Time Meter”
section for the formatting of these locations.
Pages 3-7 (03h - 07h)
The remainder of the memory in the DS2438 (Pages 3 through 7) is backed with EEPROM. This memory
provides 40 bytes of user memory which may be used to carry any information the user wishes to store.
Additionally, the CCA/DCA information is stored in bytes 4-7 of page 7 if the DS2438 is configured
appropriately. If the CCA/DCA is used, page 7 should not be written to or current accumulator data will
be overwritten. See “Operation-Current Accumulators” for details.
MEMORY MAP Figure 7
PAGE
0
1
2
BYTE
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
CONFIGURATION
END OF CHARGE
END OF CHARGE
END OF CHARGE
END OF CHARGE
TEMPERATURE
TEMPERATURE
VOLTAGE MSB
CURRENT MSB
VOLTAGE LSB
CURRENT LSB
DISCONNECT
DISCONNECT
DISCONNECT
DISCONNECT
THRESHOLD
OFFSET MSB
ETM BYTE 0
ETM BYTE 1
ETM BYTE 2
ETM BYTE 3
OFFSET LSB
CONTENTS
RESERVED
STATUS/
BYTE 0
BYTE 1
BYTE 2
BYTE 3
BYTE 0
BYTE 1
BYTE 2
BYTE 3
MSB
LSB
ICA
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
R
YES
YES
YES
YES
NV
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
16 of 29
PAGE
·
·
·
3
4
7
BYTE
·
·
·
0
1
2
3
4
6
7
3
4
5
6
7
0
1
2
3
4
5
6
7
5
0
1
2
USER BYTE/
USER BYTE/
USER BYTE/
USER BYTE/
CONTENTS
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
USER BYTE
DCA MSB
CCA MSB
DCA LSB
CCA LSB
·
·
·
R/W
·
·
·
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
YES
YES
YES
YES
YES
YES
YES
YES
·
·
·
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NV