Analog Devices EV-21569-SOM Manual page 18

Software-Controlled Switches (SoftConfig)
The Example of Bus Switch figure shows a bus switch example, reference designator UC (Pericom
PI3LVD512ZHE), selecting between lettered functionality and numbered functionality. The signals on the left side
are multiplexed signals with naming convention letter_number. The right side of the circuit shows the signals sepa-
rated into letter and number, with the number on the lower group (0B1) and the letter on the upper group (0B2).
The default setting is controlled by the signal CONTROL_LETTER_NUMBER which is pulled low. This selects the
number signals on the right to be connected to the multiplexed signals on the left by default. In this example, the
Microchip I/O expander is not shown but controls the signal CONTROL_LETTER_NUMBER and allows the user to
change the selection through software.
® 3–3
EV-21569-SOM Manual