MAX11068EVKIT+ Maxim Integrated Products, MAX11068EVKIT+ Datasheet - Page 60

• Manufacturer Part Number: MAX11068EVKIT+
• Description: KIT SMART BATT MEASUREMENT 12CH
• Manufacturer: Maxim Integrated Products

Specifications of MAX11068EVKIT+

• Main Purpose: Power Management, Battery Monitor, Car
• Utilized Ic / Part: MAX11068
• Primary Attributes: Monitors Current, Voltage, Temperature
• Secondary Attributes: 1 ~ 12 Cell- Li-Ion, 1 ~ 12 Cell- NiMH
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Embedded: -

12-Channel, High-Voltage Sensor, Smart
Data-Acquisition Interface
The ROLLCALL command is formatted like the READALL
cycle format. First, the broadcast address is sent on the
bus as an I
as a write. Next, the command 0x01 for the ADDRESS
register is sent. This address is always the target of the
ROLLCALL command. Following the broadcast address
and command byte, a repeated start is performed. Next,
the host sends another broadcast address byte with
the last bit set to 1 for an I
are forwarded up the SMBus ladder. After receiving
the broadcast address byte for the read, each device
in the chain starting with the first device responds by
sending both bytes of their ADDRESS registers. When
each device is done sending its own data, it passes
the data of the device above it in the chain. The SCL
signal provides a clock to all devices in the chain until
the host issues a stop event. Therefore, when devices
no longer have valid register data to forward, they will
continue to forward bytes consisting of 0xFF since the
SDA lines are pulled to a logic-high level. When the
host receives 2 bytes of 0xFF, it should recognize that
no more devices are present and send the NACK/stop
sequence. The stop propagates up the SMBus ladder to
halt the transfer of data. The host is then able to examine
all the bytes received and determine the number of valid
devices that are connected, in addition to the address
of the last device. If a device is connected to the chain
but not powered, its data is 0x0000 since the SDA line is
not pulled up by the VDD supplies. This allows the host
processor to determine that a device is present, but not
communicating properly or is faulty. Because of the way
Figure 33. I
60
SDA
SDA
SCL
SCL
S
2
1
2
C Communication Sequence for the SETLASTADDRESS Command
C address byte with the R/Wb bit configured
0
A0
A1
DATA
A2
2
C read. All command bytes
A3
A4
W
A
A
C7
C6
C5
C4
DATA
C3
in which data is shifted from the last device in the chain
back to the first device and then to the host, the bus
forwarding delay of the ROLLCALL command is masked
and no delay is perceived by the host once it begins
receiving data from device 1.
As an example, if a HELLOALL command was issued
previously with a starting address of 0x01, the first
device returns in response to the ROLLCALL command
the device address 0x01 encoded as 0b10100000 =
0xA0. The second device returns a device address of
0x02, which is encoded 0b10010000 = 0x90 and so on.
The last address byte is indeterminate during readback
with this command, and should not be relied upon.
This command is used to tell each MAX11068 in an
SMBus ladder which device address is the last one.
Each device must know this information to properly place
the PEC byte in the data stream during relevant com-
munication operations. The I
last device identity by using the ROLLCALL command,
which should always precede SETLASTADDRESS. Once
the last device address is known, the host initiates the
SETLASTADDRESS command to write this information to
the LA[4:0] bits of the ADDRESS register (address 0x01).
As with all data bytes in the I
byte is encoded MSB first. Figure 33 shows the I
communication sequence for the SETLASTADDRESS
command. Figure 34 shows the SETLASTADDRESS
command SMBus ladder sequences with four modules.
C2
C1
C0
A
A
SETLASTADDRESS Command
2
2
C stream, the last address
C master establishes the
PEC
A
P
2
C