STC3105

16/23

Doc ID 022198 Rev 1

7.2

Register map

The register space provides 17 control registers, 1 read-only register for device ID and 16

read/write RAM working registers reserved for the gas gauge algorithm. Mapping of all

registers is shown in

Table 10. Detailed descriptions of registers 0 (REG_MODE) and 1

(REG_CTRL) are shown in

Table 11 and Table 12. All registers are reset to default values

at power-on or reset, and the PORDET bit in register REG_CTRL is used to indicate the

occurrence of a power-on reset.

Values held in consecutive registers (such as the charge value in the REG_CHARGE_LOW

Table 10.

Register map

Name

Address

(decimal)

Type

Description

Control registers

0 to 23

REG_MODE

0

R/W

Mode register

REG_CTRL

1

R/W

Control and status register

REG_CHARGE_LOW

2

R

State-of-charge data, bits 0-7

REG_CHARGE_HIGH

3

R

State-of-charge data, bits 8-15

REG_COUNTER_LOW

4

R

Number of conversions, bits 0-7

REG_COUNTER_HIGH

5

R

Number of conversions, bits 8-15

REG_CURRENT_LOW

6

R

Battery current value, bits 0-7

REG_CURRENT_HIGH

7

R

Battery current value, bits 8-15

REG_VOLTAGE_LOW

8

R

Battery voltage value, bits 0-7

REG_VOLTAGE_HIGH

9

R

Battery voltage value, bits 8-15

REG_SOC_BASE_LOW

10

R/W

SOC base value, bits 0-7

REG_SOC_BASE_HIGH

11

R/W

SOC base value, bits 8-15

REG_ALARM_SOC_LOW

12

R/W

SOC alarm level, bits 0-7

REG_ALARM_SOC_HIGH

13

R/W

SOC alarm level, bits 8-15

REG_ALARM_VOLTAGE

14

R/W

Battery low voltage alarm level

REG_CURRENT_THRES

15

R/W

Current threshold for the voltage

relaxation counter

REG_RELAX_COUNT

16

R

Voltage relaxation counter

Device ID register

REG_ID

24

R

Part type ID = 12h

RAM registers

32 to 47

REG_RAM0

32

R/W

Working register 0 for gas gauge

...

...

...

REG_RAM15

47

R/W

Working register 15 for gas gauge