TMP91C824
91C824-56
2008-02-20
3.5.1
Port 1 (P10 to P17)
Port 1 is an 8-bit general-purpose I/O port. Each bit can be set individually for input or
output using the control register P1CR. Resetting the control register P1CR to 0 and sets
port 1 to input mode.
In addition to functioning as a general-purpose I/O port, port 1 can also function as an
address data bus (D8 to D15).
When AM1
=
0 and AM0
=
1, port 10 to 17 always operate data bus function even if it
changes P1CR setting.
Figure 3.5.1 Port 1
Int
e
rnal dat
a
bus
Direction control
(on bit basis)
P1CR write
P10 to P17
(D8 to D15)
Output buffer
Reset
P1 read
Output latch
P1 write
Port 1