The following statements from the data sheet seem to contradict each other:
5 Description (continued)
Active bus-hold circuitry holds unused or undriven data inputs at a valid logic state. Use of pullup or pulldown
resistors with the bus-hold circuitry is not recommended. The bus-hold circuitry on the powered-up side always
stays active.
10.2.1 Design Requirements
This device uses drivers which are enabled depending on the state of the DIR pin. The designer must know the
intended flow of data and take care not to violate any of the high or low logic levels. It is important that unused
data inputs not be floating, as this can cause excessive internal leakage on the input CMOS structure. Make sure
to tie any unused input and output ports directly to ground.
The reason we are using these bus-hold devices is because there could be modules that are not present, depending on the customer's configuration. These devices ensure that the missing module(s) do not cause floating inputs.
But 10.2.1 states that unused inputs and outputs should be tied to ground.
Please resolve this discrepancy.
Thanks,
Dan
