BQ2063_15 Datasheet, PDF (21/60 Pages) Texas Instruments – SBS v1.1-COMPLIANT Li-ION GAS-GAUGE IC

Not Recommended For New Designs
bq2063
SBS v1.1ĆCOMPLIANT LiĆION GASĆGAUGE IC
WITH PROTECTOR INTERFACE
SLUS468E− MAY 2001 − REVISED APRIL 2002
PEC protocol (continued)
1
7
1
ÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎ ÎÎÎÎÎÎ _S
Battery Address
0001011
0
1
8
1
A Command Code A
8
1
8
1
Data Byte Low A Data Byte High A
8
PEC
Write Word
11
ÎÎÎÎ_{A P}
1
7
11
8
11
7
11
ÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎÎ ^S
Battery Address
0001011
0
A Command Code A
S Battery Address 1
A
8
1
8
1
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ^{Data Byte Low A Data Byte High} A
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Read Word}
8
PEC
11
AP
1
7
11
8
11
7
11
ÎÎÎ ÎÎ ÎÎ _{S Battery Address 0 A Command Code A S Battery Address 1 A}
ÎÎÎ ÎÎ ÎÎ ^0001011
8
1
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{ByteCount= N A}
8
1
Data Byte 1 A
8
1
Data Byte 2 A
8
1
Data Byte N A
8
PEC
11
AP
Block Read
Host Processor
ÎÎÎÎÎÎbq2063
A − ACKNOWLEDGE
A − NOT ACKNOWLEDGE
S − START
P − STOP
Figure 9. SMBus Communication Protocol With PEC
PEC calculation
The basis of the PEC calculation is an 8-bit Cyclic Redundancy Check (CRC-8) based on the polynomial
C(X) = X8 + X2 + X1 + 1. The PEC calculation includes all bytes in the transmission, including address,
command, and data. The PEC calculation does not include ACKNOWLEDGE, NOT ACKNOWLEDGE, START,
STOP, and Repeated START bits.
For example, the host requests RemainingCapacity( ) from the bq2063. This includes the host following the
Read Word protocol. The bq2063 calculates the PEC based on the following 5 bytes of data, assuming the
remaining capacity of the battery is 1001 mAh.
D Battery Address with R/W = 0: 0x16
D Command Code for RemainingCapacity( ): 0x0f
D Battery Address with R/W = 1: 0x17
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
21