Hitachi MB-6890, Руководство по обслуживанию

Страница: 29 / 123

I-lDZ4E.S\
ZSAEP
(Quadruple
Bus
Buffer Gates
5-29
Consists
Of
4
pieces of three
state
gates
with.
Three-State
Outputs() When control
input (C) is
Low,
the
space
between
(M
input
(A)
and
output (Y) becomes
buffer and
output
V"
"
3 " 3’
becomes
High
Impedance "HZ" when
control input (C)
U
U
EH’
U
’H
is (H).
E
>
lik
lin
I
I I
~
I
I I
|¢
|| IV
2C
ZA Z7 GNU
AS-29
=HD2=lE}Sl3§§_
(3_|__ine tc,
3-Line
Decoder)
5-30
consists
of
3 line-8
line
decoder,
Ougmt
One of the 8
output
line
of 3 select
input and
(sv)
,
Y _
3 select
input
and 3 enable
input. The
I/O
v
Y
,___ c. ._ _
t- e i ~
- - -’
’ ’
" "
relatlon lS
as
per
table
5-6
1n
next
page.
z
GB
Q
YI
Yz
Yx
Ya Ys
E
m
I3 |
Z I ¢
O
9
vo vu YI
YI Y*
Y
A
YI
5
Yr
3
C
G
A
.
1 2
B
B
6
8
A
B C
Gu Gil
G*
Y’
GND
sem:
"input Enabw input
output
.3-30
Hnz-msiaseir
(Dual
2~Line
to
4-Line
5-31
COF¢sists of
two independent 2
line-4 line
Decoders/Demultiplexers) GGCOUSP /
Select
Input
D
t Q
_
E ’ § § ’ ’ § ’ j §
t
Decoding/demultiplexing
is
dependent
upon
the
,S
m
,4 ,, .2
,.
.O
9
2 select, and enable
pins.
IG IA IB
|Yu |Y| |Yz lY| GND
Enable?
ect
Input
Dan
Output
7"v