HP 5383A

Table 8-1 . M a j o r Sig n al Defi n itio n s
M od
el 5383 Α
M ai n tenance
Mnemonic Description
A, B,C,D Display Data Bu s BCD lines ( W eig h t : Α =1, Β =2, C=4, D=8) .
M G TT L ve r sio n of M G E ; u se
d
to co
n
t
r
ol R STB L
atc h .
M
G
E
M
ain gate cont r ol sig n al (EE C L logic level) ; allows i npu t to f r e qu en cy
coun te r s (w h en L ow) .
MR S Co un ter r eset a nd d isplay d igit test comma nd (ge
n
e r ate
d
by R S
sig
n al) .
O
F Ove r flow ;
low
TT L level i nd icates ove r flow of fre qu e n cy coun te r s .
RB I R ip p le B la nk i n g I n pu t ; low TT L level allows b la nk
i n g
of ze r os i n d is p lay ;
h ig h TT L level i nh ibits ze r o b la nk i
n g .
RB O Rip p le
Blan k i ng
O
u
t pu
t ;
low
TT L level w h e n ze r os a r e b la nked f r om
d is p lay ;
h ig h TT L level at all ot h e r times .
R S H ig h TT L level r esets co u nte r w he n GAT E TIME switc h posi-
tio n is ch ange d .
P rovi d es d isplay d igit test w h en GAT E TIME switc
h
is h el d b etween
positio n s .
_ R SC
R
SC
TT L signals t
h
at r eset f r e qu e
n
cy co un te
r
s .
R STB TT L signals t h at r eset t h e va r ia b le Time B ase cou nte r a nd M ai n Gate
R STB L atc h es dur i ng t he upd ate se qu e n ce (see F ig ur e 4-3) .
50 ΤΗ RU S9 E ig h t con ti n uo u sly cyclyi ng d is p lay scan sig n als ; eac
h
sca n li n e activates
one d isplay d igit .
Τ _ R
TT
L signals t h
at
tra n sfe r f r e qu ency co u nte r B CD d ata to t he sto r age
T R latc h es dur i ng t he up d ate se q ue nce (see F ig ur e 4-3) .
W U se d fo r o u t pu t m u ltiplexi n g of t h e H ex Mu ltiplexe d Deca de Co un te r
B CD c h a r acte r s . T h ese sig n als also dr ive t h eΗυ B CD-to-Decimal ιοη
-
Ζ
ve r te r p r oviding t he Scan sig n als (50 t hru S9) .
._1s
L ow
TT L level t h at ill u minate t h e LE D d is p lay d ecimal p oi n ts and co n t r ol
1s
lea d
i n g
ze
r o blan k i n g .
111s