NEC PD78F9488 Manuale Utente
CHAPTER 4 PORT FUNCTIONS
76
User’s Manual U15331EJ4V1UD
Table 4-1. Port Functions
Port Name
Pin Name
Function
Port 0
P00 to P07
I/O port. Input/output can be specified in 1-bit units.
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B0 (PUB0) or the key return mode register (KRM00).
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B0 (PUB0) or the key return mode register (KRM00).
Port 1
P10, P11
I/O port. Input/output can be specified in 1-bit units.
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B1 (PUB1).
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B1 (PUB1).
Port 2
P20 to P25
I/O port. Input/output can be specified in 1-bit units.
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B2 (PUB2).
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B2 (PUB2).
Port 3
P30 to P34
I/O port. Input/output can be specified in 1-bit units.
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B3 (PUB3).
When used as an input port, an on-chip pull-up resistor can be specified in 1-bit units by
pull-up resistor option register B3 (PUB3).
Port 5
P50 to P53
N-ch open-drain I/O port. Input/output can be specified in 1-bit units.
An on-chip pull-up resistor can be specified by mask option.
An on-chip pull-up resistor can be specified by mask option.
Port 6
P60 to P67
Input port
Port 7
Note 1
P70 to P73
Input port (only when input port is selected by mask option or port function register)
Port 8
Note 2
P80 to P87
I/O port (only when I/O port is selected by mask option or port function register)
Notes 1. Whether to use these pins as input port pins (P70 to P73) or segment outputs (S16 to S19) can be
selected in 1-bit units by means of a mask option in the
µ
PD789488, 789489 or a port mode register in
the
µ
PD78F9488, 78F9489 (refer to 4.3 (3) Port function registers and CHAPTER 20 MASK
OPTIONS).
2. Whether to use these pins as I/O port pins (P80 to P87) or segment outputs (S20 to S27) can be
selected in 1-bit units by means of a mask option for the
µ
PD789488, 789489 or a port mode register in
the
µ
PD78F9488, 78F9489 (refer to 4.3 (3) Port function registers and CHAPTER 20 MASK
OPTIONS).
4.2 Port Configuration
Ports have the following hardware configuration.
Table 4-2. Configuration of Port
Item Configuration
Control registers
Port mode registers (PMm: m = 0 to 3, 5, 8)
Pull-up resistor option registers (PUB0 to PUB3)
Port function registers (PF7, PF8) (
Pull-up resistor option registers (PUB0 to PUB3)
Port function registers (PF7, PF8) (
µ
PD78F9488, 78F9489 only)
Ports
Total: 45 (CMOS I/O: 29, CMOS input: 12, N-ch open-drain I/O: 4)
Pull-up resistors
• Mask ROM version
Total: 25 (software control: 21, mask option specification: 4)
• Flash memory version
Total: 21 (software control only)
Total: 25 (software control: 21, mask option specification: 4)
• Flash memory version
Total: 21 (software control only)