LeCroy Waverunner2 LT262 Series, Руководство по обслуживанию

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4-16 Theory of Operation
4.2.5
µ
P Control
Control between the microprocessor and the main board is accomplished via the
RPM. The RPM functions are:
•
Processor interface
•
MAM interface
•
8 bit bus interface (MTB411, MCG426, MST429A, IIC)
•
Serial interface
•
Min-Max Computation
•
Histogram
•
RPM is configured at boot up by the processor. The RPM configuration program
is stored in the flash memory.
4.2.6 Trigger
The different trigger couplings are :
•
DC
•
AC : cut off frequency is almost 7.5 Hz.
•
LF REJ : single pole high pass filter with a cut off frequency at 50
kHz.
•
HF REJ : single pole low pass filter with a cut off frequency at 50 kHz.
•
HF : frequency divider by four.
Analog Controls
A sample and hold fed by the precision DAC provides the threshold levels. A
precision DAC is also used for a successive approximation ADC which measures
Probus inputs, temperature, etc.
4.2.7 Analog to Digital Converter
Introduction
The analog to digital converter system does the signal conversion to 8 bits, using
the following circuits:
•
HSY632: Hybrid switching AMP 2 in 4 out.
•
HAM631 : Hybrid ADC 1GS/s with 4Mb memory. Provide 83 MHz clock for
memory and refresh for DRAM