BQ2063_15 Datasheet, PDF (19/60 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
0001011 (bits 7-1) plus a R/W bit (bit 0) followed by an SMBus command code. The R/W bit (LSB) and the
command code instruct the bq2063 to either store the forthcoming data to a register specified by the SMBus
command code or output the data from the specified register. The processor completes the access with a STOP
condition. A STOP condition consists of a low-to-high transition of the SMBD line while the SMBC is high. With
SMBus, the most-significant bit (MSB) of a data byte is transmitted first.
In some instances, the bq2063 acts as the bus master. This occurs when the bq2063 broadcasts charging
requirements and alarm conditions to device addresses 0x12 (SBS Smart Charger) and 0x10 (SBS Host
Controller.)
SMBus protocol
The bq2063 supports the following SMBus protocols:
D Read Word
D Write Word
D Block Read
A processor acting as the bus master uses the three protocols to communicate with the bq2063. The bq2063
acting as the bus master uses the Write Word protocol.
The SMBD and SMBC pins are open drain and require external pullup resistors. If detection of an SMBus Off
State is required when the SMBC and SMBD lines are open, a 1-MΩ pulldown resistor in the battery pack is
recommended.
SMBus packet error checking
The bq2063 supports Packet Error Checking as a mechanism to confirm proper communication between it and
another SMBus device. Packet Error Checking requires that both the transmitter and receiver calculate a Packet
Error Code (PEC) for each communication message. The device that supplies the last byte in the
communication message appends the PEC to the message. The receiver compares the transmitted PEC to its
PEC result to determine if there is a communication error.
PEC protocol
The bq2063 can receive or transmit data with or without PEC. Figure 8 shows the communication protocol for
the Read Word, Write Word, and Read Block messages without PEC. Figure 8 includes PEC.
In the Write Word protocol, the bq2063 receives the PEC after the last byte of data from the host. If the host does
not support PEC, the last byte of data is followed by a STOP condition. After receipt of the PEC, the bq2063
compares the value to its calculation. If the PEC is correct, the bq2063 responds with an ACKNOWLEDGE. If
it is not correct, the bq2063 responds with a NOT ACKNOWLEDGE and sets an error code.
In the Read Word and Block Read, the host generates an ACKNOWLEDGE after the last byte of data sent by
the bq2063. The bq2063 then sends the PEC and the host acting as a master-receiver generates a NOT
ACKNOWLEDGE and a STOP condition.
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