HD6433308 HITACHI [Hitachi Semiconductor], HD6433308 Datasheet - Page 103

• Manufacturer Part Number: HD6433308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

5.5 Port 4
Port 4 is an 8-bit input/output port that also provides the input and output pins for the 8-bit timers
and the output pins for the PWM timers. The pin functions depend on control bits in the control
registers of the timers. Pins not used by the timers are available for general-purpose input/output.
Table 5-8 lists the pin functions, which are the same in both the expanded and single-chip modes.
Table 5-8. Port 4 Pin Functions (Modes 1 to 3)
Usage
I/O port
Timer
See section 7, “8-Bit Timer Module” and section 8, “PWM Timer Module” for details of the timer
control bits.
Pins of port 4 can drive a single TTL load and a 90pF capacitive load when they are used as output
pins. They can also drive a Darlington pair. When used as input pins, they have programmable
MOS pull-ups.
Table 5-9 details the port 4 registers.
Table 5-9. Port 4 Registers
Name
Port 4 data direction register
Port 4 data register
Port 4 Data Direction Register (P4DDR)—H’FFB5
Bit
Initial value
Read/Write
P4DDR is an 8-bit register that selects the direction of each pin in port 4. A pin functions as an
output pin if the corresponding bit in P4DDR is set to “1,” and as an input pin if the bit is cleared to
“0.”
Pin functions
P4
TMCI
0
P4
0
7
W
DDR P4
7
0
P4
TMO
1
0
6
W
DDR P4
6
0
P4
TMRI
Abbreviation
P4DDR
P4DR
2
0
5
W
DDR P4
5
0
P4
TMCI
3
1
88
4
Read/Write
W
R/W
W
DDR P4
P4
TMO
4
0
4
1
3
P4
TMRI
W
DDR P4
3
0
5
Initial value
H’00
H’00
1
P4
PW
2
W
DDR P4
2
0
6
0
P4
PW
1
W
DDR P4
1
0
7
Address
H’FFB5
H’FFB7
1
0
W
DDR
0
0