TM 5-6675-320-14
b. The functions are accomplished by the following functional units:
S i g n a l l i n es
Select code decoder circuit
I / O r e g i s t e r d e c o d e r c i r c u it
Computer command register circuit
I / O d a t a r e g i s t e r c i r c u i t
C o m p u t e r i n t e r r u p t l o g i c c i r c u it
C o n t r o l l o g i c c i r c u i t
I n t e r r u p t l o g i c c i r c u i t
H P - I B t r a n s c e i v e r c i r c u it
HP-IB output data latch circuit
HP-IB address register circuit
H P - I B i n p u t m u l t i p l e x e r c i r c u it
H P - I B c o n t r o l b u s l a t c h c i r c u it
P a r a l l e l p o l l l o g i c c i r c u it
( 1 ) S i g n a l l i n e s c a r r y t h e d a t a,
information, and control signals between
the HP-IB interface ROM, the computer and the plotter (Tables 4-1 and 4-2). Signal
lines can be grouped by function into four groups:
Data lines
T r a n s f e r l i n es
C o n t r o l l i n es
I / O l i n es
(2) Data lines are found on both sides of the HP-IB Interface. They contain
all the signals that communicate data, including input, output and program codes;
address control; and status information.
Transfer lines hold the signals that
control the transfer of each byte of information between the plotter (via HP-IB) and
the HP-IB interface (either to or from).
Signals on the control lines are primary
control signals and govern the flow of information over both the transfer and data
lines between the HP-IB interface and the plotter.
Signals on the I/O lines perform
the same functions between the HP-IB Interface and computer, as those on the
transfer and control lines do between the HP-IB Interface and the plotter.
4-7
