Datasheet

bq2050 Registers
The bq2050 command and status registers are listed in
Table 7 and described below.
Command Register (CMDR)
The write-only CMDR register is accessed when eight
valid command bits have been received by the bq2050.
The CMDR register contains two fields:
n
W/R bit
n
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
76543 2 1 0
W/R
- -- - - - -
Where W/R is:
0 The bq2050 outputs the requested register con
-
tents 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.
Primary Status Flags Register (FLGS1)
The read-only FLGS1 register (address=01h) contains
the primary bq2050 flags.
The charge status flag (CHGS) is asserted when a
valid charge rate is detected. Charge rate is deemed
valid when V
SRO
>V
SRQ
.AV
SRO
of less than V
SRQ
or
discharge activity clears CHGS.
The CHGS values are:
Where CHGS is:
0 Either discharge activity detected or V
SRO
<
V
SRQ
1V
SRO
>V
SRQ
The battery replaced flag (BRP) is asserted whenever
the bq2050 is reset either by application of V
CC
or by a
serial port command. BRP is reset when either a valid
charge action increments NAC to be equal to LMD, or a
valid charge action is detected after the EDV1 flag is as
-
serted. BRP = 1 signifies that the device has been reset.
The BRP values are:
Where BRP is:
0 Battery is charged until NAC = LMD or dis
-
charged until the EDV1 flag is asserted
1 bq2050 is reset
10
FLGS1 Bits
76543 2 1 0
CHGS - -- - - - -
CMDR Bits
765 4 3 2 1 0
- AD6 AD5 AD4 AD3 AD2 AD1
AD0
(LSB)
TD205002.eps
DQ
Break 0 0 0 0 0 0 1 0 1 0 0 1
Written by Host to bq2050
CMDR = 03h
Received by Host to bq2050
NAC = 65h
LSB MSB LSB MSB
1110
Figure 3. Typical Communication With the bq2050
bq2050
FLGS1 Bits
76543 2 1 0
- BRP - - - - - -