AD8197B Analog Devices, AD8197B Datasheet - Page 17

• Manufacturer Part Number: AD8197B
• Description: 4:1 HDMI/DVI Switch with Equalization
• Manufacturer: Analog Devices

PARALLEL CONTROL INTERFACE
The AD8197B can be partially controlled through the parallel
interface using the PP_EN, PP_CH[1:0], PP_EQ, PP_PRE[1:0],
PP_OTO, and PP_OCL pins. Logic levels for the parallel
interface pins are set in accordance with the specifications listed
in Table 1. Setting these pins updates the parallel control
interface registers, as listed in Table 18. Following a reset, the
AD8197B can be controlled through the parallel control
interface until the first serial control event occurs. As soon as
any serial control event occurs, the serial programming values
override any prior parallel programming values, and the parallel
control interface is disabled until the part is subsequently reset.
The default serial programming values correspond to the state
of the serial interface configuration registers, as listed in Table 5.
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Note that after changing the status of the channel selection
(PP_CH[1:0]), it is necessary to assert a low logic level to
RESET to ensure that the channel select status is properly
updated.
Note also that the input termination resistor switches can be
controlled only via serial programming. Therefore, as most
systems require controlling these resistors, serial control is
required and parallel control is of little use. However, the
parallel control pins determine the AD8197B status between
the time of the assertion of reset and the first serial program-
ming event.
AD8197B