Table 1. Triple–Mode Segment Decoder Function Table
Lamp Conditions
Bank Nibble Value
Binary
Hexadecimal MSB LSB
7–Segment Display
Characters
Hex Decode
(Invoked via
Bits C1 to C5)
Special
Decode
(Invoked via
Bits C1 to C7)
No Decode
(Invoked via
Bits C1 to C7)
d
c
b
a
$0
L LL L
$1
L LL H
$2
L LH L
$3
L LH H
on
on
on on
$4
L HL L
on
$5
L HL H
$6
L HH L
$7
L HH H
on
on
on on
on on on
$8
H LL L
$9
H LL H
$A
H LH L
on
on
on
on
on
$B
H LH H
on
on on
$C
H HL L
on on
$D
H HL H
on on
on
$E
H HH L
on on on
$F
H HH H
on on on on
NOTES:
1. In the No Decode mode, outputs e, f, and g are unused and are all forced inactive (low). Output
h decoding is unaffected, i.e., unchanged from the other modes. The No Decode mode is used
for three purposes:
a. Individually controlling lamps.
b. Controlling a half digit with sign.
c. Controlling annunciators - examples: AM, PM, UHF, kV, mm Hg.
2. Can be used as capital S.
3. Can be used as capital B.
4. Can be used as small g.
MOTOROLA
MC14489
9