Tektronix OPTION 10 Service Supplement Manual page 10

464 and 466 Opt ion 1 0
Exam ple
Finding t he Out put s of ROM U3605 . In t his discussion
we will assum e t he CHOP/ ALT but t on is depressed .
Given : Vert ical Mode
|
Present ly
displayed
CH 2
1 . In Figure Opt ion 1 0-4 , find t he colum n t hat m at ches
t he present display on t he screen of t he oscilloscope .
Desired
CH 1 and TRIG VIEW
( CHOP/ ALT but t on
pressed in )
The colum n headings appear by nam e and num ber
as Trigger Vi ew , 01 1; Add , 1 00 ; Ch 2 , 1 01; and
Ch 1 , 1 1 0. The digit s represent t he logic levels on
t he feedback
lines from
FF U3705 t o ROM
U3605 .
Find :
Logic
levels at t he out put s of
U3605 for
t ransit ion and operat ion .
Procedure :
( Refer t o Figure 1 0-4 for det ails of t his pro
cedure .)
a . Find colum n for present operat ing m ode ( CH 2 ) .
a
2. Locat e t he row of dat a t hat pert ains t o t he new
operat ing m ode of t he 464/ 466 .
C
b . Find row of dat a for CH 1 and TRIG VIEW . This row
has digit s 1 1 001, which m eans :
CH 1
C
Do t his by looking in t he " Present" dat a colum n at
t he left end of t he t able for a com binat ion of 1 's and
a
O's t hat represent s t he front - panel cont rol set t ings .
( A
1 " represent s a depressed pushbut t on .) The left
m ost digit , bit 7 , will be a " q " when t he A TIME/
DIV cont rol is not in X Y posit ion .
TRIG VIEW
A TIME/ DIV is not in X Y posit ion
C
c . Find t he num ber at t he int ersect ion of t he colum n
and row you locat ed in part s a and b . The num ber is
1 1 1 0 , which m eans :
run t he chop clock
go t o colum n headed 1 1 0
( CH 1)
w
3. Find t he four - bit binary num ber at t he int ersect ion of
t he row and colum n you locat ed in st eps 1 and 2. The
out put s of U3605 should have t hese levels . Of t he
four bit s , t he m ost - significant , 04 , cont rols t he chop
clock ( 1 m eans " run t he clock " ) , and t he ot her t hree
m ean " go t o t he colum n wit h t his heading." The
lat t er t hree bit s ident ify t he channel t hat will be dis
played on screen when U3705 receives t he next clock
pulse,
This m eans t hat CH 1 will be displayed when U3705
receives t he next clock pulse .
d . Find t he num ber at t he int ersect ion of colum n 1 1 0
( CH 1 ) and t he row of part b . The num ber is 1 01 1,
which m eans :
run t he chop clock
go t o colum n headed 01 1
( TRIG VIEW )
4. Find t he colum n whose heading num ber m at ches t he
last t hree bit s of t he num ber you locat ed in st ep 3 .
)
This m eans t hat t he TRIG VIEW signal will be di s
played when U3705 receives t he next clock pulse .
5. Locat e t he num ber appearing at t he int ersect ion of
t his new colum n and t he row you locat ed in st ep 2 .
e . Find t he num ber at t he int ersect ion of colum n 01 1
and t he row found in part b . The num ber is 1 1 1 0 ,
which m eans :
run t he chop clock
6. Find t he colum n whose heading m at ches t he last
t hree bit s of t he num ber you locat ed in st ep 5 .
go t o colum n headed 1 1 0 ( CH 1 )
a
1
7. Locat e t he num ber appearing at t he int ersect ion of
t his colum n and t he row you found in st ep 2 .
The sequence of operat ions we find in part s c , d , and
e shows t hat t he ROM and FF should operat e in a CH
1 , TRIG VIEW , CH 1 ... sequence . 1
C
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