Theory of Operation
2715 Spectrum Analyzer Service Manual 3-53
At the end of a horizontal bin the contents of the Max Accumulator will be
written to waveform memory.
If the acquisition mode is Min Peak thesame comparisons occur as in Max Peak
acquisition mode, except that the Min Accumulatoris used. At the end of a
horizontal bin the contents of theMin Accumulator will be written to waveform
memory.
If the acquisition mode is Min/Max thenthe same comparison occur as in Max
Peak acquisition mode, except that both theMin and Max Accumulators are
used. At the end of a horizontal bin the contents of either the Max or Min
Accumulators will be written into waveformmemory, depending on whether the
horizontal bin was even or odd andwhether noise was detected or not. Noise is
defined as both the Min and Max Accumulatorbeing written with a new value
sometime during the horizontal bin. Table3--13 shows the algorithmused to
write data to the waveform memory at the end of a horizontalbin.
Table3 -13: Input Conditions Required to Write Either the Max or Min
Accumulators to Waveform Memory
Horizontal Bin Signal Type Waveform Written From
Odd Noise Max Accumulator
Odd Si gnal MaxAccumulator
Even Noise MaxAccumulator
Even Signal Max Accumulator
If the acquisition mode is Sample the incoming data is automatically placed in
the Max Accumulator, regardlessof its value. At the end of the horizontal bin,
the contents of the Max Accumulatorare written to waveform memory. This
effectively places the last acquisition, from the ADC, into waveform memory.
The timing diagram in Figure 3--19 shows the sequence of events required when
writing data to the waveformmemory.