TM 11-7025-221-20
1-16. Multiplexer Section Block Diagram Discussion (V3/V4 Models).
M proc card A11 contains the microprocessor and controls TD-1337(V)/8 operation. Data are trans-
ferred between the microprocessor and other cards over an 8-bit hi-directional data bus.
Front panel A23 provides for operator interface. Display card A23A1 provides the operator with
information via a 3-line display and five alarm indicators. Keyboard A23A2 is used to enter instructional
data or cause messages to be displayed.
NVM card A9 contains non-volatile memory (NVM) circuits that retain configuration data entered
by the operator. Up to two operating configurations can be entered and retained. A battery, on
the card, provides power to the memory circuits when the TD-1337(V)/G is turned off or input
ac power is lost.
A remote interface function provides for sending (or receiving) configuration data in NVM to (or
from) a standby TD-1337(V)/G.
An address decoding function decodes addresses from M proc card A11 to generate I/O read/write
strobes. These strobes allow the microprocessor to communicate (write and read data) with other
cards over the 8-bit data bus.
The synthesizer circuit on SSV card A2 produces a mux clock output. The rate of the mux clock
is dependent on system operating configuration and will be between 16 kHz and 4664 kHz in
8 kHz steps. Rate of SG output is equal to rate of the mux clock.
The rate measurement circuit on loop modem/rt mess card A4 measures the frequency of selected
timing signals within the TD-1337(V)/G. The frequency of each selected timing signal is counted
