Keyboard Controller Circuit - Panasonic JS-170FR Series Service Manual

2.1.5.5

Keyboard controller circuit

The IT8673F is used for keyboard control.
The internal memory block of the IT8673F has programs for the keyboard control and the control with the main CPU.
The IT8673F internally converts the serial data sent from the keyboard into parallel data, and performs interrupt operation to
inform the CPU of the entry of a key input.
The operation clock is set at 8MHz in the internal register.
The fuse connected to Pin 4 of the connector is used to protect the curl cord from burning in case the power supply circuit is
short-circuited on the keyboard side.
I T 8 6 7 3 F
8 6
G A 2 0
A2 0 GAT E
8 3
R C I N # K R S T #
+ 5 V
1 0 K
8 0
K B C L K
8 1
M S D ATA
8 2
M S C L K
8 1
K B D ATA
N0 1 0 0 5 5 9 V1 0 5
PS/ 2 M O U S E
Q_ A
1 0 K
U N2 2 1 2
M A7 4 6
1 0
1 0
M A7 4 6
Q _ B
D_ A
U N 2 2 1 2
M A 1 5 2 W A
Q _ C
U N2 2 1 2
M A74 6
1 0
1 0
M A7 4 6
Q_ D
U N2 2 1 2
M A 1 5 2 W A
2-23
+ 5 V
C N _K/B
4 7 0 K
L
L
1 0 0 p
L
L
+ 5 V
2 A
M I N I - D I N
+ 5 V
4 7 0 K
1 0 0 p
D_ B
3
G M D
5
K B / C L K
1
K B / D ATA
2
M S / D ATA
6
M S / C L K
4
V D D