TMP91C824
91C824-64
2008-02-20
3.5.5
Port 7 (P70 to P72)
Port 7 is a 3-bit general-purpose I/O port. I/O can be set on bit basis using the control
register. Resetting sets port 7 to input port and all bits of output latch to 1.
In addition to functioning as a general-purpose I/O port, port 7 also functions as follows.
1. Input/output function for serial bus interface (SCK, SO/SDA.SI/SCL)
2. Input/output function for IrDA (OPTRX0, OPTTX0)
Writing 1 in the corresponding bit of P7FC, P7FC2 enables the respective functions.
Resetting resets the P7FC, P7FC2, and P7CR to 0, and sets all bits to input ports.
(1)
Port 70 (SCK, OPTRX0)
Port 70 is a general-purpose I/O port. It is also used as SCK (Clock signal for SIO
mode) and OPTRX0 (Receive input for IrDA mode of SIO0).
Used as OPTRX0, it is possible to logical invert by P7<P70>
=
0.
For port C1, RXD0 or OPTRX0 is used P7FC2<P70F2>.
Figure 3.5.9 Port 70
Int
e
rnal dat
a
bus
Selector
A
B
S
Selector
A
B
S
P70 (SCK, OPTRX0)
SCK output
P7 read
Direction
control
(on bit basis)
P7CR write
Function
control
(on bit basis)
S
Output latch
P7 write
Reset
P7FC write
SCK input
Function
control 2
(on bit basis)
P7FC2 write
Selector
A
B
S
RXD0
(to SIO0)
RXD0PC1
(from PORTC1)
logical invert