Measurement Block; Measurement Block Circuit Description - HP 5334B Service Manual

8-170. MEASUREMENT BLOCK
8-171. All HP 5334B measurement functions and data manipulation are performed in the Measurement Block
under the control of the Measurement Microcomputer (MCU) which receives its instructions from the Executive
MCU.
8-172. The Measurement Block has four major components: The Measurement MCU, the Multiple-Register
Counter (MRC), the Multi-Function Chip (MFC), and the Interpolator Counters.
8-173. Inputs to this block are from the Input Amplifier, Digital-to-Analog Converter (DAC), Channel C, and
Time Base blocks.
8-1 74. Measurement Block Circuit Description
8-175. The overall measurement cycle is controlled by the Measurement MCU (U29). In addition to the com-
ponents in the Measurement Block, it controls the DAC, and Channel C blocks. Also, in the Input Amplifier
Block, the Measurement MCU sets threshold voltages through the DAC Block and sets operator-selected
parameters through the Relay Driver (U37).
8-176. The operation of the measurement cycle centers on the continuous interaction between Measurement
MCU U29, MRC U20, and MFC U14. The MRC is a programmable Large-System Integration (LSI) counter-on-
a-chip containing the registers that accumulate the input measurement data. The MFC is an LSI device that per-
forms various interface functions between the MRC and inputloutput devices.
8-177. The last part of the block, the Interpolator Counter section, works with the MRC and the MFC to
measure the inherent error factor generated in the normal measurement routine, using an analog interpolation
technique. The data it sends to the Measurement MCU is used to improve the accuracy of the measurement.
8-178. The Measurement MCU implements the input signal conditioning and front panel setup as instructed by
the Executive MCU, and then initiates the measuremeat cycle by sending instructions to the MRC U20. Instruc-
tion data including measurement mode, selection of input, slope, gate timiig, and means of arming are written
into the MRC control register through the Cline I10 data bus port (DO to D3). Data is transferred to and from
the MRC over the Measurement Data Bus, and controlled by the CHIP SELECT (CS), READtWRITE (RIW),
and STROBE (STR) lines from the Measurement MCU.
8-179. The Measurement MCU has four &bit 110 ports, for a total of 32 UO lines. Eight lines are used to send
and receive data over the Measurement Data Bus. The other 24 lines are control lines associated with the
Counter's functions.
8-180. The Multiple-Register Counter (MRC) contains four registers. The CONTROL register sets up the
measurement mode of the MRC and resets the counting registers, synchronizers, and overflow flags as directed
by the Measurement MCU. The EVENT register counts pulses from the input signal, while the TIME register
counts the 10-MHz time base pulses used as the reference. The STATUS register contains EVENT and TIME
register overflow flags and information on the measurement status.
8-181. The Multi-Function Chip (MFC) contains five functionally independent circuits, four of which are used
for MRC interfacing. MFC circuits include a Channel C multiplexer, an Arming multiplexer, two Interpolators,
and a T i e Base buffer.
HP 5334B
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Service Manual
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