AD8191 Analog Devices, AD8191 Datasheet - Page 18

• Manufacturer Part Number: AD8191
• Description: 4:1 DVI/HDMI Switch with Equalization Preliminary Data Sheet (Rev. PrJ, 8/2006)
• Manufacturer: Analog Devices

AD8191
SERIAL CONTROL INTERFACE
RESET
On initial power-up, or at any point in operation, the AD8191
register set can be restored to pre-programmed default values
by pulling the RESET pin to low according to the specification
in Table 1. During normal operation, however, the RESET pin
must be pulled up to 3.3 V. The pre-programmed default values
correspond to the state indicated by the parallel control
interface pins. Once the AD8191 is reset, the part can be
controlled through the parallel control interface until the first
serial control event occurs.
WRITE PROCEDURE
To write data to the AD8191 register set, an I
a microcontroller) needs to send the appropriate control signals
to the AD8191 slave device. The signals are controlled by the
I
procedure, see
follows:
1.
2.
3.
4.
2
P
C master unless otherwise specified. For a diagram of the
P
Send a start condition (while holding the I2C_SCL line
high, pull the I2C_SDA line low).
Send the AD8191 part address (seven bits). The upper four
bits of the AD8191 part address are the static value [1001]
and the 3-LSBs are set by the Input Pins I2C_ADDR2,
I2C_ADDR1 and I2C_ADDR0 (LSB). This transfer should
be MSB first.
Send the write indicator bit (0).
Wait for the AD8191 to acknowledge the request.
F igure 14. The steps for a write procedure are as
X
2
P
C master (such as
P
Figure 14. I
Rev. PrJ | Page 18 of 29
2
C Write Diagram
5.
6.
7.
8.
9.
Send the register address (eight bits) to which data is to be
written. This transfer should be MSB first.
Wait for the AD8191 to acknowledge the request.
Send the data (eight bits) to be written to the register
whose address was set in Step 5. This transfer should be
MSB first.
Wait for the AD8191 to acknowledge the request.
Do one of the following:
9a. Send a stop condition (while holding the I2C_SCL
9b. Send a repeated start condition (while holding the
9c. Send a repeated start condition (while holding the
9d. Send a repeated start condition (while holding the
line high, pull the I2C_SDA line high) and release
control of the bus to end the transaction (shown in
Figure 14).
I2C_SCL line high, pull the I2C_SDA line low) and
continue with Step 2 in this procedure to perform
another write.
I2C_SCL line high, pull the I2C_SDA line low) and
continue with Step 2 of the read procedure (in the
Read Procedure section) to perform a read from
another address.
I2C_SCL line high, pull the I2C_SDA line low) and
continue with Step 8 of the read procedure (in the
Read Procedure section) to perform a read from the
same address set in Step 5.
Preliminary Technical Data