DS2764 High-Precision Li+ Battery Monitor With 2-Wire Interface

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Table 2. Memory Map

ADDRESS (HEX)

DESCRIPTION

READ/WRITE

00

Protection Register

R/W

01

Status Register

R

02–06

Reserved

07

EEPROM Register

R/W

08

Special Feature Register

R/W

09–0B

Reserved

0C

Voltage Register MSB

R

0D

Voltage Register LSB

R

0E

Current Register MSB

R

0F

Current Register LSB

R

10

Accumulated Current Register MSB

R/W

11

Accumulated Current Register LSB

R/W

12–17

Reserved

18

Temperature Register MSB

R

19

Temperature Register LSB

R

1A–1F

Reserved

20–2F

EEPROM, block 0

R/W*

30–3F

EEPROM, block 1

R/W*

40–47

EEPROM, block 2

R/W*

50–EF

Reserved

F0–F7

Unique ID

R

+

F8–FD

Reserved

FE

Function Command Register

W

FF

Reserved

* Each EEPROM block is read/write until locked by the LOCK command, after which it is read-only.

+ Unique 64 bit ID is a factory option available by special order. Units with IDs do not allow access to block 2 of user EEPROM

PROTECTION REGISTER

The protection register consists of flags that indicate protection circuit status and switches that give conditional

control over the charging and discharging paths. Bits OV, UV, COC, and DOC are set when corresponding

protection conditions occur and remain set until cleared by the host system. The default values of the CE and DE

bits of the protection register are stored in lockable EEPROM in the corresponding bits in address 30h. A recall

data command for EEPROM block 1 recalls the default values into CE and DE. Figure 11 shows the format of the

protection register. The function of each bit is described in detail in the following paragraphs.

Figure 11. Protection Register Format

ADDRESS 00

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

OV

UV

COC

DOC

CC

DC

CE

DE

OV—Overvoltage Flag. When set to 1, this bit indicates the battery pack has experienced an overvoltage condition.

This bit must be reset by the host system.

UV—Undervoltage Flag. When set to 1, this bit indicates the battery pack has experienced an undervoltage

condition. This bit must be reset by the host system.

COC—Charge Overcurrent Flag. When set to 1, this bit indicates the battery pack has experienced a charge-

direction overcurrent condition. This bit must be reset by the host system.

DOC—Discharge Overcurrent Flag. When set to 1, this bit indicates the battery pack has experienced a discharge-

direction overcurrent condition. This bit must be reset by the host system.