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Whenever you use one of the opamps its dedicated pins will be in use and cannot be used by another component. The router is able to connect that opamp to another pin when required, but the dedicated pins will still be in use. So the route is "hopping" from the dedicated pin to the target.
This was used to have low-impandence connections for some of the internal devices to the outside.
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Modificatiuon to what Bob said. Just the OpAmp output pin becomes dedicated,
not its inputs.
Opamp Pin Selection
The opamps are connected to the GPIOs in such a way that they can be used without
any internal analog global busses, See Figure 12. If all connections to the opamp are
external through the GPIOs, it is a good idea to use the dedicated pins. In many cases,
the opamp may be used as a buffer to an internally generated signal, such as a buffer to
a VDAC output. In this case the dedicated opamp input pins may be ignored and used for
another purpose. After the opamp is enabled, the dedicated output GPIO will always be
driven by the output of the opamp. This GPIO is now dedicated to the opamp output and
cannot be used for another signal. Even if this signal is only used internally, the dedicated
output pin will be driven by the opamp. This guarantees that the resistance between the
opamp and GPIO pin is low, about 5 ohms. If you must use a different pin for the output,
the dedicated output pin still outputs the signal. If the opamp is not used, it has no affect
on the GPIOs directly connected to it. These GPIO pins operate as any of the other GPIOs
when the opamp is disabled.
Makes one wonder if the output pin can be over-ridden with a register write.
After all out R in the path of an OpAmp output, its effective Zo becomes divided
by loop gain.