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 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 |