Rainbow Electronics MAX7358 - Manual (Page 18)

MAX7356/MAX7357/MAX7358
1-to-8 I
2
C Bus Switches/Multiplexers with Bus
Lock-Up Detection, Isolation, and Notification
18 ______________________________________________________________________________________
edge bit because the device is the recipient. When the
MAX7356/MAX7357/MAX7358 are transmitting to the
master, the master generates the acknowledge bit
because the master is the recipient.
Slave Address
The MAX7356/MAX7357/MAX7358 have 7-bit-long
slave addresses (Figure 6). The eighth bit following the
7-bit slave address is the R/W bit. It is low for a write
command, and high for a read command.
Accessing the MAX7356
A single-byte write to the MAX7356 sets the switch
control register.
A multibyte write to the MAX7356 writes repeatedly to
the switch control register. The last byte written deter-
mines the contents of the register.
A single-byte read from the MAX7356 returns the con-
tents of the switch control register.
A multibyte read (2 or more bytes before the I 2 C STOP
bit) from the MAX7356 returns the contents of the
switch control register repeatedly.
Accessing the MAX7357/MAX7358 in
Enhanced Mode
In enhanced mode, all 7 registers are enabled. These
registers are autoincremented starting with the switch
control register during each I
2 C transaction. When a
new transaction begins, the switch control register is
the first register accessed.
A single-byte write to the MAX7357 or MAX7358 sets
the switch control register.
A 2-byte write to the MAX7357 or MAX7358 sets the
switch control and configuration registers.
A 3-byte write to the MAX7357 or MAX7358 sets the
switch control, configuration, and flush-out sequence
registers.
A multibyte write to the MAX7357 or MAX7358 with
more than three bytes sets the first three registers, then
resets the pointer back to the switch control register
(0x00) since the remaining registers are read only.
Subsequent bytes of data, after 3 bytes, begin overwrit-
ing the first set of data starting with 0x00, 0x01, 0x02,
then looping back to 0x00 again, and continuing until a
STOP condition is received.
A single-byte read from the MAX7357 or MAX7358
returns the contents of the switch control register.
A multibyte read from the MAX7357 or MAX7358 returns
contents of all 7 registers in sequence and repeats.
The internal register address count always begins with
the switch control register, 0x00.
Accessing the MAX7357/MAX7358
in Basic Mode
In basic mode, only the switch control register is
enabled.
A single-byte write to the MAX7357 or MAX7358 sets
the switch control register.
A multibyte write to the MAX7357 or MAX7358 in basic
mode writes repeatedly to the switch control register.
The last byte written determines the contents of the reg-
ister.
A single-byte read from the MAX7357 or MAX7358
returns the contents of the switch control register.
A multibyte read (2 or more bytes before the I 2 C STOP
bit) from the MAX7357 or MAX7358 returns the contents
of the switch control register repeatedly.
Writing to the MAX7356
The MAX7356’s switch control register can be written by
an I
2 C write command starting with the device address
for the MAX7356 and followed by data bytes. The last
data byte is stored into the switch control register.
A write to the MAX7356 starts with the master transmitting
the slave address with the R/W bit set low. The MAX7356
acknowledges the slave address. The master can then
issue a STOP condition after the acknowledge (Figure 14),
but typically the master proceeds to transmit one or more
bytes of data. The MAX7356 acknowledges these subse-
quent bytes of data and updates the switch control regis-
ter when the master issues a STOP condition (Figure 14).
Writing to the MAX7357/MAX7358 in
Enhanced Mode
The MAX7357 and MAX7358 registers can be written
by an I
2 C write command starting with the device
address for the MAX7357 or MAX7358 and followed by
data bytes. The first data byte is stored into the switch
control register and subsequent data bytes are stored
into the subsequent registers.
A write to the MAX7357 or MAX7358 starts with the
master transmitting the slave address with the R/W bit
set low. The MAX7357 or MAX7358 acknowledge the
slave address. The master can then issue a STOP con-
dition after the acknowledge (Figure 15), but typically