9.8 Port 7
9.8.1 Overview
Port 7 is an 8-bit input/output port with the pin configuration shown in figure 9-19. Its pins also
carry input and output signals for the on-chip free-running timers (FRT1, FRT2, and FRT3), and
two input signals for the on-chip 8-bit timer.
Port 7 has Schmitt inputs. Outputs from port 7 can drive one TTL load and a 30 pF capacitive
load. They can also drive a Darlington transistor pair.
9.8.2 Port 7 Registers
Register Configuration:
Table 9-13 lists the registers of port 7.
Table 9-13 Port 7 Registers
Name
Port 7 data direction register
Port 7 data register
Abbreviation
P7DDR
P7DR
Read/Write
W
R/W
Initial Value
H'00
H'00
Address
H'FE8C
H'FE8E
1. Port 7 Data Direction Register (P7DDR)—H'FE8C
P7DDR is an 8-bit register that selects the direction of each pin in port 7. A pin functions as an
output pin if the corresponding bit in P7DDR is set to 1, and as an input pin if the bit is cleared to 0.
P7
7
(input/output) / FTOA
1
(output)
P7
6
(input/output) / FTOB
3
(output) / FTCI
3
(input)
P7
5
(input/output) / FTOB
2
(output) / FTCI
2
(input)
P7
4
(input/output) / FTOB
1
(output) / FTCI
1
(input)
P7
3
(input/output) / FTI
3
(input) /TMRI (input)
P7
2
(input/output) / FTI
2
(input)
P7
1
(input/output) / FTI
1
(input)
P7
0
(input/output) / TMCI (input)
Port
7
Figure 9-19 Pin Functions of Port 7
Bit
7
6
5
4
3
2
1
0
P7
7
DDR P7
6
DDR P7
5
DDR P7
4
DDR P7
3
DDR P7
2
DDR P7
1
DDR P7
0
DDR
Initial value
0
0
0
0
0
0
0
0
Read/Write
W
W
W
W
W
W
W
W
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