Toshiba TLCS-900/H1 Series Manual page 148

3.7.21 Port X (PX4, PX5)
Port X5 is 1-bit general-purpose I/O ports. Each bit can be set individually for input or
output. Resetting sets ports X5 to input port and output latch to "0".
In addition to functioning as general-purpose I/O port, PX5 can also function as the USB
clock input pin (X1USB) and dividing clock output of X1 and X2 oscillation clock
Setting in the corresponding bits of PXCR and PXFC enables the respective functions.
Port X4 is 1-bit general-purpose output port. Resetting sets output latch to "0".
In addition to functioning as general-purpose output port, PX4 can also function as a
system clock output pin (CLKOUT).
Setting in the corresponding bits of PX and PXFC enables the respective functions.
(on bit basis)
Output latch
PX read
CLKOUT output
Reset
Function
control
PXFC write
R
A
PX write
Selector
B
S
A
Selector
Figure 3.7.56 Port X4
92CF30-146
S
TMP92CF30
(X1D4).
PX4 (CLKOUT)
2009-06-12