BQ27520-G4 Datasheet, PDF (18/34 Pages) Texas Instruments – System-Side Impedance Track Fuel Gauge

bq27520-G4
SLUSB20B – NOVEMBER 2012 – REVISED DECEMBER 2015
www.ti.com
Table 2. Extended Data Commands
Reserved
DataFlashClass( ) ⁽²⁾
DataFlashBlock( ) ⁽²⁾
BlockData( )
BlockDataCheckSum( )
BlockDataControl( )
ApplicationStatus( )
Reserved
NAME
COMMAND
CODE
0x34 to 0x3D
0x3E
0x3F
0x40 to 0x5F
0x60
0x61
0x6A
0x6B to 0x7F
UNIT
NA
NA
NA
NA
NA
NA
NA
NA
(1) SEALED and UNSEALED states are entered via commands to Control( ) 0x00 and 0x01.
(2) In sealed mode, data flash cannot be accessed through commands 0x3E and 0x3F.
SEALED
ACCESS^{(1) (2)}
R
NA
RW
R
RW
NA
R
R
UNSEALED
ACCESS^{(1) (2)}
R
RW
RW
RW
RW
RW
R
R
8.5.3 Communications
8.5.3.1 I²C Interface
The bq27520-G4 fuel gauge supports the standard I²C read, incremental read, quick read, one byte write, and
incremental write functions. The 7-bit device address (ADDR) is the most significant 7 bits of the hex address
and is fixed as 1010101. The first 8-bits of the I²C protocol is, therefore, 0xAA or 0xAB for write or read,
respectively.
Host generated
Gauge generated
S ADDR[6:0] 0 A CMD [7:0] A DATA [7:0] A P
S ADDR[6:0] 1 A DATA [7:0]
(a) 1-byte write
(b) quick read
S ADDR[6:0] 0 A CMD [7:0] A Sr ADDR[6:0] 1 A DATA [7:0] N P
(c) 1- byte read
NP
S ADDR[6:0] 0 A
CMD [7:0]
A Sr ADDR[6:0] 1 A
(d) incremental read
DATA [7:0]
A ...
DATA [7:0]
NP
S ADDR[6:0] 0 A CMD[7:0] A DATA [7:0] A DATA [7:0] A . . . A P
(e) incremental write
(S = Start , Sr = Repeated Start , A = Acknowledge , N = No Acknowledge , and P = Stop).
Figure 8. I²C Read, Incremental Read, Quick Read, One Byte Write, and Incremental Write Functions
The “quick read” returns data at the address indicated by the address pointer. The address pointer, a register
internal to the I²C communication engine, increments whenever data is acknowledged by the fuel gauge or the
I²C master. “Quick writes” function in the same manner and are a convenient means of sending multiple bytes to
consecutive command locations (such as two-byte commands that require two bytes of data).
The following command sequences are not supported:
Attempt to write a read-only address (NACK after data sent by master):
Figure 9. Invalid Write
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