DA1 select the connections of switch A to switch SW_

and inputs DB0 and DB1. Select the connections of

switch B to SW_. See Table 3a for the pin configuration

and Table 3b for a complete summary.

In mode 1, the switch connections are controlled

registers R0 and R1. Register R0, bits [7 to 2], select

the connection of switch A and switch B to switch SW_

(see the

The bits of register R1 transfer data to the output DO_.

The data on output DO_ is used to communicate with the

MAX3845. In mode 1, DA0/DO0 becomes output DO0,

DA1/DO1 becomes output DO1, DA2/DO2 becomes

output DO2, and DB0/DO3 becomes output DO3. DB1

and DB2 are high impedance. See Table 3a for the pin

configuration. See Table 4 for register R1 to DO_ output

mapping.

Two internal registers (RO and R1) program the

MAX4814E. Table 2 lists both registers, their address-

es, and power-up default states. Both registers are

read/write registers.

In register R0, bit BAEN is used as the enable for

switch A, and bit BBEN is used as the enable for switch

B. Writing 1 to bit BAEN enables switch A; and writing 0

to bit BAEN disables switch A. Writing 1 to bit BBEN

enables switch B, and writing 0 to bit BBEN disables

switch B. BASEL1 and BASEL0 select the connections

of switch A to switch SW_, while BBSEL1 and BBSEL0

select the connections of switch B to switch SW_, as

summarized in Table 6.

The two LSBs are hard coded as 00. Register R0

ignores any value written to the two LSBs; anytime reg-

ister R0 is read the hard-coded values are returned.

Bank A Enable (BAEN) and Bank B Enable (BBEN) Bits

1 = Enable

0 = Disable

Bank A Select (BASEL1/BASEL0) and

Bank B Select (BBSEL1/BBSEL0) Bits

Bits BASEL1 and BASEL0 select the switch SW_ that

switch A is connected to. Bits BBSEL1 and BBSEL0

select the switch SW_ that switch B is connected to

(see Table 6).

Power-On Default States

When power is applied to the MAX4814E internal

power-on reset (POR), circuitry sets registers R0 and

R1 to their default states. Register R0 is set to all zeros,

or 00h, and register R1 is set to 10101010, or AAh, as

shown in Table 2.

Having all zeros in register R0 disables both banks A

and B; see Table 6 for register R0 to switch mapping.

Setting register R1 to AAh forces the outputs at DO_ to

be high impedance.

Note: The output, DO_ is used to communicate with the

MAX3845 when the MAX4814E is being used without its

companion. The MAX3845 and the MAX4814E use the

connected through a 10kΩ resistor to GND.

DVI/HDMI 2:4 Low-Frequency Fan Out Switch

10

______________________________________________________________________________________

X = Hardwired code, not programmable by user.

Table 1. Mode Configuration

INPUT PIN

MODE

OPERATION

0

Puts the device in mode 0. The direct-control inputs DA_ and DB_ control the switches.

1

Inputs DB1 and DB2 are high impedance.

BIT

POWER-UP

REGISTER

7

6

5

432

1

0

ADDRESS

BINARY

HEX

R0

BBEN

BBSE

L1

BBSEL0

BAEN

BASEL1

BASE

L0

X

X

0x00

0000

0000

00

R1

DO3

High

Impedance

DO3

Data

DO2

High

Impedance

DO2

Data

DO1

High

Impedance

DO1

Data

DO0

High

Impedance

DO0

Data

0x01

1010

1010

AA