w83c42 Winbond Electronics Corp America, w83c42 Datasheet - Page 8

• Manufacturer Part Number: w83c42
• Description: Keyboard Controller
• Manufacturer: Winbond Electronics Corp America

ELECTRICAL CHARACTERISTICS & CAPACITANCE
(Ta = 0 C to +70 C, V
STATUS REGISTER
The status register is an 8-bit read-only register at I/O address hex 64 that holds information about the
state of the keyboard controller and interface. It may be read at any time.
SYMBOL
BIT
0
1
2
3
4
5
V
V
V
V
R
I
I
V
T
C
I
LO
OL
DD
OH
OL
LI
IH
A
IL
IP
L
Output Buffer Full
Input Buffer Full
System Flag
Command/data
Inhibit Switch
Transmit Time Out
BIT DESCRIPTION
Power Supply
Operating Temperature
High Level Voltage for TTL
Min. I/P
Low Level Voltage for TTL
Max. I/P
High Level Voltage for TTL
Min. O/P
Low Level Voltage for TTL
Max. O/P
Min. I/P Resist
I/P Leakage Current
O/P Leakage Current
O/P Sink Current
O/P Load Capacity
DD
= +5V 5%)
DESCRIPTION
0: Output Buffer Empty
1: Output Buffer Full
0: Input Buffer Empty
1: Input Buffer Full
This bit may be set to 0 or 1 by writing to the system flag bit in
the command byte of the keyboard controller. It is set to 0 after
a power-on reset
0: Data Byte
1: Command Byte
0: Keyboard is Inhibited
1: Keyboard is Not Inhibited
0: No Transmit Time Out Error
1: Transmit Time Out Error
- 8 -
V
DD
MIN.
4.75
10K
-0.3
2.0
-10
-10
15
0
4
-0.5
FUNCTION
TYP.
5.0
25
MAX.
5.25
V
0.8
0.5
70
10
10
50
DD
W83C42
UNIT
mA
pF
V
V
V
V
V
V
A
A