Philips pm2521 - Page 186

14
10.8.
Test
5
(Counter and
counter input control test).
Settings
signature analyser
Setting
Edge
Testpoint
Signalname
start
(neg) TP14 P17
stop
J'
(pos)
TP14 P17
clock
if
(pos) TP15
ALE
ground
—
TP1 logic
0
NOTE:
1.
Testrom
placed in D 1909
socket (Both
ROMs
removed)
2. Short
circuit TP
10
and TP
11
3.
Reading on display:
L5
4.
Connect point 1
of
D1910 to logic 0
5. Adjust
with
R502
the signature on D
19
11
point 2 to 0000
6.
Select
the signature on point
15
of D
1903
with the
+/—
button: 154H
7.
Reference logic
0
=
0000
logic 1
=3UH7
[A -
CLOCK AOC
s
01
IJ
C'<
L^3niAn.'\j
-1
I
'
=
JCI903
.
IToop
f
4
.11. .1.1 -
Sracii
ADC
u
R
'
IALEI
*0000
ICT/ADCPIOl
{
PFFQ
IaZC/P
PISI
COUNTER
INPUT
CONTROL
f
®
Ni
anaI
*—£2!dE_
ll3
0000
fC
nianaI
.
L7
J
»0000
LOGIC 0
=
0000
LOGIC 1 = 3UH7
’Apigii
74LS86