BQ27510-G2 Datasheet, PDF (31/38 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Direct Battery Connection

bq27510-G2
www.ti.com
COMMUNICATIONS
SLUS948 – AUGUST 2010
I²C INTERFACE
The fuel gauge supports the standard I²C read, incremental read, one-byte write quick read, and functions. The
7-bit device address (ADDR) is the most significant 7 bits of the hex address and is fixed as 1010101. The 8-bit
device address is therefore 0xaa or 0xab for write or read, respectively.
Host generated
Fuel gauge generated
S
ADDR[6:0]
0A
CMD[7:0]
A
DATA[7:0]
AP
S
ADDR[6:0]
1A
DATA[7:0]
(a) 1- byte write
S
ADDR[6:0]
0A
CMD[7:0]
A Sr
ADDR[6:0]
1A
(b) quick read
DATA[7:0]
NP
S
ADDR[6:0]
0A
CMD[7:0]
A Sr
(c) 1 byte read
ADDR[6:0]
1A
(d) Incremental read
DATA[7:0]
A ...
DATA[7:0]
(S = Start, Sr = Repeated Start, A = Acknowledge, N = No Acknowledge, and P = Stop)
Figure 5. Supported I²C Formats
NP
NP
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 bq27510-G2 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).
Attempt to write a read-only address (NACK after data sent by master):
S ADDR[6:0] 0 A CMD[7:0]
A DATA[7:0]
NP
Attempt to read an address above 0x6B (NACK command):
S
ADDR[6:0]
0 A CMD[7:0] N P
Attempt at incremental writes (NACK all extra data bytes sent):
S
ADDR[6:0]
0A
CMD[7:0]
A
DATA[7:0]
A
DATA[7:0]
N ... N P
Incremental read at the maximum allowed read address:
S
ADDR[6:0]
0A
CMD[7:0]
A Sr
Address
0x7F
ADDR[6:0]
1A
DATA[7:0]
A
DATA[7:0]
Data from
addr 0x7F
NP
Data from
addr 0x00
Copyright © 2010, Texas Instruments Incorporated
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