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.