Bit Counter, Timing Diagram; Eight-Character Counter, Logic Diagram - Raytheon DIDS-400 Series Technical Manual

DIDS-402-2AM13
j-t--
ONE CHARACTER TIME (13 f-Is)---,
Ala.11 - PHASE 2
I
A20.13
1
I
A20.8
'"Il
L
I
A19.a 1
i
A25.6 - CTS
LJ
L
I
A25. 12 - CTS+1
-;--L.J
L
I
A25. a - CTS+4&5
I
-..f
I- 1.625
IJS
A24.8 - CTS
11
r--L-
DIDS 68-656
Figure 4-57. Bit Counter, Timing Diagram
4-24.5 Eight-Character Counter
The eight-character counter (figure 4-58) is a divide -by-eight counter
which produces outputs corresponding to every seventh and eighth CTS developed
by the bit counter. The timing diagram for the eight-character counter is shown
in figure 4-59. These outputs are not used external to the timing circuits, but
assist in developing important time markers such as last word of line (LWL), end
of line (EOL), and first word of line (A). The eight-character decode produces
an output once every eight character times. This output is used to clock the
character counter. .
CTS
DIDS 68-657
8TH CHARACTER
COUNTER
12 9 12
AIS AIS AID
13 8
13
CTS
CTS
r6_~.
CTS OF 8TH CHARACTER
8
~---t.CT!= OF 7TH CHARACTER
Figure 4-58. Eight-Character Counter, Logic Diagram
4-140