XC2200 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
User’s Manual
7-11
V2.1, 2008-08
Parallel Ports, V1.6D6
Function of the PCx and PSx bit fields
Note: If a bit position is not written (one out of two bytes not targeted by a byte write), the
corresponding value is considered as 0. Toggling a bit requires one 16-bit write.
Field
Bits
Type Description
PSx
(x = 0-7)
x
w
Port Set Bit x
Setting this bit sets or toggles the corresponding bit in
the port output register Pn_OUT (see
).
On a read access, this bit returns X.
PCx
(x = 0-7)
x + 8
w
Port Clear Bit x
Setting this bit clears or toggles the corresponding bit
in the port output register Pn_OUT. (see
).
On a read access, this bit returns X.
Table 7-3
Function of the Bits PCx and PSx
PCx
PSx
Function
0 or no write access
0 or no write access
Bit Pn_OUT.Px is not changed.
0 or no write access
1
Bit Pn_OUT.Px is set.
1
0 or no write access
Bit Pn_OUT.Px is cleared.
1
1
Bit Pn_OUT.Px is toggled.