BQ2012_15 Datasheet, PDF (11/26 Pages) Texas Instruments – Gas Gauge IC With Slow-Charge Control

Not Recommended For New Designs
bq2012
Written by Host to bq2012 Received by Host to bq2012
CMDR = 03h
NAC = 65h
LSB
MSB LSB
MSB
Break 1 1 0 0 0 0 0 0 1 0 1 0 0 1 1 0
DQ
TD201201.eps
Figure 3. Typical Communication With the bq2012
Command Register (CMDR)
The write-only CMDR register is accessed when eight
valid command bits have been received by the bq2012.
The CMDR register contains two fields:
I W/R bit
I Command address
The W/R bit of the command register is used to select
whether the received command is for a read or a write
function.
The W/R values are:
CMDR Bits
7
65
4
3
2
1
0
W/R - -
-
-
-
-
-
Where W/R is:
0 The bq2012 outputs the requested register
contents specified by the address portion of
CMDR.
1 The following eight bits should be written
to the register specified by the address por-
tion of CMDR.
The lower seven-bit field of CMDR contains the address
portion of the register to be accessed. Attempts to write
to invalid addresses are ignored.
CMDR Bits
765 4
3
2
1
0
-
AD6 AD5 AD4
AD3
AD2
AD1
AD0
(LSB)
Primary Status Flags Register (FLGS1)
The read-only FLGS1 register (address=01h) contains
the primary bq2012 flags.
The charge status flag (CHGS) is asserted when a
valid charge rate is detected. Charge rate is deemed
valid when VSRO > VSRQ. A VSRO of less than VSRQ or
discharge activity clears CHGS.
The CHGS values are:
FLGS1 Bits
7
65
4
3
2
1
0
CHGS - -
-
-
-
-
-
Where CHGS is:
0 Either discharge activity detected or VSRO <
VSRQ
1 VSRO > VSRQ
The battery replaced flag (BRP) is asserted whenever
the potential on the SB pin (relative to VSS), VSB, falls
from above the maximum cell voltage, MCV (2.25V), or
rises above 0.1V. The BRP flag is also set when the
bq2012 is reset (see the RST register description). BRP
is reset when either a valid charge action increments
NAC to be equal to LMD, or a valid charge action is de-
tected after the EDV1 flag is asserted. BRP = 1 signifies
that the device has been reset.
The BRP values are:
FLGS1 Bits
7
65
4
3
2
1
0
- BRP -
-
-
-
-
-
Where BRP is:
0 Battery is charged until NAC = LMD or dis-
charged until the EDV1 flag is asserted
1 VSB dropping from above MCV, VSB rising
from below 0.1V, or a serial port initiated
reset has occurred
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