18.3.2.5 Virtual Ports

The Virtual PORT registers map the most frequently used regular PORT registers into the I/O Register space with single-cycle bit access. Access to the Virtual PORT registers has the same outcome as access to the regular registers but allows for memory specific instructions, such as bit manipulation instructions, which cannot be used in the extended I/O Register space where the regular PORT registers reside. The following table shows the mapping between the PORT and VPORT registers.
Table 18-2. Virtual Port Mapping
Regular PORT RegisterMapped to Virtual PORT Register
PORTx.DIRVPORTx.DIR
PORTx.OUTVPORTx.OUT
PORTx.INVPORTx.IN
PORTx.INTFLAGSVPORTx.INTFLAGS
Note: Avoid accessing the mapped VPORT register using the single-cycle I/O instructions immediately after accessing the regular PORT register. This may cause a memory collision since the single-cycle I/O access to VPORT is faster than the regular PORT register access.