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 ordinary registers allowing 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 1. Virtual Port Mapping
Regular PORT Register Mapped to Virtual PORT Register
PORTx.DIR VPORTx.DIR
PORTx.OUT VPORTx.OUT
PORTx.IN VPORTx.IN
PORTx.INTFLAGS VPORTx.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.