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4430-V & VN BPSK/QPSK VME Demodulator & Optional Modulator User’s Manual
Doc: 4430_V,VN.fm, © 11 Jul 2005, 14:55
Table 3.5.12: Modulator Carrier Frequency NCO Group Register Definition
Programming
Example
1.
For the programming example given, the following equation must be
evaluated:
Register Value = Mod fc x 214.74837
Register Value = 8000 x 214.74837 = 1717986.96
2.
Rounding results as shown below:
Register Value = 1717987
3.
By successively dividing the above value by the bit weight values shown in
figure above, the appropriate hexadecimal equivalent can be obtained:
Register Value = 001A36E3h
4.
Cleave the results into the four respective registers and write as shown:
Register 23h= 00h
Register 22h= 1Ah
Register 21h= 36h
Register 20h= E3h
Bit No.
Bit Name(s)
Functional Description
31-24
Mod Carrier Frequency
Most significant carrier frequency word (See
Figure
3.5.12
for register assignments)
25-16
Mod Carrier Frequency
Carrier frequency word 3 (See
Figure 3.5.12
for register
assignments)
15-8
Mod Carrier Frequency
Carrier frequency word 2 (See
Figure 3.5.12
for register
assignments)
7-0
Mod Carrier Frequency
Least significant carrier frequency word (See
Figure
3.5.12
for register assignments)
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