MAX4549 Maxim, MAX4549 Datasheet - Page 13

• Manufacturer Part Number: MAX4549
• Description: The MAX4548/MAX4549 serial-interface, programmable, triple 3x2 audio/video crosspoint switches are ideal for multimedia applications
• Manufacturer: Maxim

Figure 5. 2-Wire Serial-Interface Timing Details
Table 3. Bias Data-Byte (C6 = “1”)
The devices are programmed with a command byte and
a data byte or data word (2 bytes). Each bit of the
command byte selects one of the functional blocks to be
controlled by the subsequent data byte (word). The data
byte (word) sets the state of the selected block(s). For
the three switch-matrix blocks, the data byte sets the
switch state. For the bias-resistor block, the data word
D15
D14
D13
D12
D11
D10
BIT
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
SCL
SDA
Don’t care
Don’t care
Don’t care
Don’t care
Controls SC bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO3C bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO2C bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO1C bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls SB bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls SA bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO3B bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO3A bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO2B bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO2A bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO1B bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
Controls NO1A bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors.
t
SU:STA
Serially Controlled, Triple 3x2 Audio/Video
A
t
HD:STA
Command-Byte and Data-Byte
______________________________________________________________________________________
t
LOW
B
t
HIGH
A = START CONDITION
B = MSB OF ADDRESS BYTE
C = LSB OF ADDRESS BYTE
D = ACKNOWLEDGE CLOCKED INTO MASTER
E = MSB OF COMMAND BYTE
t
SU:DAT
C
Programming
D
t
HD:DAT
DESCRIPTION
E
controls which bias network is active (see Functional
Diagram ).
A logic “1” in any bit position of the data byte makes
that function active, while a logic “0” makes it inactive.
Tables 1–4 describe the command byte and the corre-
sponding data byte. If more than one bit of the com-
mand byte is set, the data byte programs all of the
corresponding blocks. This operation is useful, for
instance, to simultaneously set all switch matrices to
F = LSB OF COMMAND BYTE
G = ACKNOWLEDGE CLOCKED INTO MASTER
H = MSB OF DATA BYTE/WORD
I = LSB OF DATA BYTE/WORD
J = ACKNOWLEDGE CLOCKED INTO MASTER
F
Crosspoint Switches
G
H
I
J
t
SU:STO
POWER-UP
DEFAULT
t
BUF
STATE
1
1
1
1
1
1
1
1
1
1
1
1
–
–
–
–
13