Renesas 4513 Manual De Usuario
4513/4514 Group User’s Manual
APPLICATION
2-7
2.1 I/O pins
2.1.3 Port application examples
(1)
Key input by key scan
Key matrix can be set up by connecting keys externally because port D output structure is an N-
channel open-drain and port P0 has the pull-up resistor.
Key matrix can be set up by connecting keys externally because port D output structure is an N-
channel open-drain and port P0 has the pull-up resistor.
Outline: The connecting required external part is just keys.
Specifications: Port D is used to output “L” level and port P0 is used to input 16 keys. Multiple key
Specifications: Port D is used to output “L” level and port P0 is used to input 16 keys. Multiple key
inputs are not detected.
Figure 2.1.1 shows the key input and Figure 2.1.2 shows the key input timing.
Fig. 2.1.1 Key input by key scan
SW4
SW3
SW2
SW8
SW7
SW6
SW9
SW11
SW10
SW12
SW16
SW15
SW14
SW13
D
0
D
1
D
2
D
3
P0
0
P0
1
P0
2
P0
3
SW1
SW5
M34513/M34514