TMP91C824
91C824-73
3.5.8
Port D (PD0 to PD7)
Port D is an 8-bit output port. Resetting sets the output latch PD to “1”, and PD5 to PD7 pin output “1”.
In addition to functioning as output port, Port D also function as output pin for output pin for internal
clock (SCOUT), output pin for RTC alarm (/ALARM) and output pin for melody/alarm generator
(MLDALM,/MLDALM). Above setting is used the function register PDFC.
Only PD6 has two output functions which /ALARM and /MLDALM. This selection is used PD<PD6>.
Resetting resets the function register PDFC to “0”, and sets all ports to output ports.
Function control
(On bit basis)
Output latch
PD read
Reset
PD7(MLDALM)
MLDALM
Output buffer
Se
le
c
to
r
PDFC write
PD write
S
A
B
In
te
rn
a
l d
a
ta
b
u
s
Figure 3.5.23 Port D
In
te
rn
a
l d
a
ta
b
u
s
Fs clock
Reset
S
Output latch
PD write
PD read
Function control
(On bit basis)
PDFC write
S
A
Y
Selector
B
f
SYS
clock
SYSCR2<SCOSEL>
PD5 (SCOUT)
A
Y
Selector
B
S
Figure 3.5.24 Port D