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AL6300 DATA LINK TEST SET PRODUCT LINE
6.2
GENERATING PCM DATA STREAMS
DDS
As detailed in Figure 20 above, the DLTM4 provides the ability to generate PCM data streams in addition to PRN data.
This note provides a few examples of simple PCM streams used to test links and other equipment in the data link system.
5.4.10
BASICS
Two steps are required to define a TDM PCM data stream:
•
describe the overall PCM frame format
•
define the data values to be placed in it.
6.2.1.1 PCM SETUP
A separate menu is provided that allows the PCM frame to be defined:
•
Sync Pattern
•
Bits per Word (all words in the frame are the same length)
•
Words per Frame
•
MSB / LSB first (which direction the data is serialized)
6.2.1.2 EDIT PCM
This menu allows up to 32 instructions to be entered that control the content of the output TDM PCM frame. At the start
of each TDM PCM frame, the first instruction in the list is executed, and then the second and so on until the last word of
the frame (as defined by the Words per Frame setup) is output. Then the process repeats.
The instructions are simple:
LOAD FSP
LOAD IMM
REPEAT
FR CNT
The LOAD IMM instruction allows unique values to be placed anywhere in the frame. It can also be used with the
REPEAT instruction to output a series of the same value (General / Background value).
A
L
, I
.
POGEE
ABS
NC
PRN GENERATOR
LOCAL
BIT CLOCK
EXTERNAL (ST)
PCM FRAME
GENERATOR
WORD,
FRAME
MARKS
PCM DATA GENERATOR
ADRS
PCM PROGRAM MEMORY
Figure 20: DLTM Transmitter Block Diagram
Output the 1st and 2nd 16 bits (or fraction thereof if Bits per Word is < 16 bits) of the
Sync Pattern
Output the data value immediately following this command
Repeat the previous LOAD instruction 'n' times
Outputs a count per frame (setup the Frame Counter)
PRN
PCM
PARALLEL
DATA
CONTROL
& DATA
23
210 South 3
09.21.2017
MODEL 2349 DLTM4
ERROR INSERT,
CODE CONVERT,
TO TX
OUTPUT
POLARITY
INTERFACES
SELECT
rd
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