Theory of Operation
3–12
TDS 340A, TDS 360 & TDS 380 Technical Reference
The NVRAM (U605) consists of a single nonvolatile memory IC. This RAM
provides long-term power-off storage of front-panel settings, waveforms, and
calibration constants.
Dynamic RAM U704 is organized as 256 K
16 for a total of 512 kbytes. It is
controlled by the ADG250 display controller (U701).
During a normal 68331 access the ADG250 multiplexes the address (on A2 to
A19) onto the A0 to A8 address lines and creates control signals ~RAS, ~CAS,
~XWL, ~XWU, and ~XOE.
A display controller IC processes text and waveforms. The display system sends
the text and waveform information to the monitor assembly as a video signal.
The display system also generates vertical (VSYNC) and horizontal (HSYNC)
sync signals for the monitor assembly.
The display circuit’s primary function is writing waveforms into waveform
planes. The circuitry provides Vector, Dot, Vector Accumulate, Dot Accumulate,
XY, and YT display modes.
The display system provides text, graticule, and waveform bit planes. All
information displayed is first written to a plane. Planes are stored in dedicated
DRAMS along with the vector lists. The information is sent at regular refresh
intervals as an analog video signal.
The waveform display circuit takes a list of sample points, translates them into
intensities for the bit map, writes those intensities to the bit map in the proper
location, and interrupts the CPU when it is done.
— Four vector lists available from U706 store waveform sample
data. Before starting a normal display mode, the CPU writes data to a vector list.
Rasterizers.
The display controller (U701) provides two rasterizers. Their
primary function is to “draw” vectors between sample points. The display
controller also performs the top and bottom clip display functions on waveforms.
Video Timing.
Q701–Q704 and associated circuitry convert digital video signals
from the display controller into an analog video signal, with two levels con-
trolled by VIDEO LEVEL and INTENS LEVEL from the daculator. The display
controller also creates monitor timing HSYNC (31.25 Hz) and VSYNC (60 Hz).
U703D, U708D, and U709 generate AUX HSYNC, AUX VSYNC and AUX
VIDEO for the Option 14 VGA Video output connector.
Display System
Summary of Contents for TDS 340A
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Page 12: ...Contents viii TDS 340A TDS 360 TDS 380 Technical Reference ...
Page 16: ...Service Safety Summary xii TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 42: ...Operating Information 2 10 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 49: ...Theory of Operation 3 6 TDS 340A TDS 360 TDS 380 Technical Reference ...
Page 59: ...Theory of Operation 3 16 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 82: ...Performance Tests 4 22 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 91: ...Adjustment Procedures 5 8 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 140: ...Troubleshooting 6 48 TDS 340A TDS 360 TDS 380 Technical Reference ...
Page 142: ...Repackaging Instructions 6 50 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 206: ...Electrical Parts List 8 58 TDS 340A TDS 360 TDS 380 Technical Reference ...
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Page 210: ...TDS 340A 360 380 OPTION BOARD BLOCK DIAGRAM A2 0 ...
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Page 212: ...OPTION BUS AND GPIB A2 TDS 340A 360 380 1 ...
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Page 214: ...TDS 340A 360 380 ROM PRINTER AND RS 232 A2 2 ...
Page 216: ...PRINTER POWER A3 1 TDS 340A 360 380 OPTION 14 ...
Page 218: ...A5 1 FLOPPY INTERFACE TDS 340A 360 380 ...
Page 222: ...CPU A6 TDS 340A 360 380 1 ...
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Page 224: ...A6 TDS 340A 360 380 2 FPP POTS ...
Page 225: ......
Page 226: ...LEDS DRIVER A6 TDS 340A 360 380 3 ...
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Page 228: ...SWITCHES A6 TDS 340A 360 380 4 ...
Page 233: ...9 26 TDS 340A TDS 360 TDS 380 Technical Reference ...
Page 234: ...ROOT SHEET A11 A12 TDS 340A 360 0 ...
Page 235: ......
Page 236: ...TRIGGERS A11 A12 TDS 340A 360 1 TDS 340A ...
Page 237: ......
Page 238: ...ATTENUATORS A11 A12 TDS 340A 360 2 TDS 340A TDS 340A ...
Page 239: ......
Page 240: ...TRIGGER LOGIC AND TIME INTERPOLATOR A11 A12 TDS 340A 360 3 ...
Page 241: ......
Page 242: ...TIME BASE CONTROLLER A11 A12 TDS 340A 360 4 ...
Page 243: ......
Page 244: ...SAMPLER A11 A12 TDS 340A 360 5 ...
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Page 246: ...CPU A11 A12 TDS 340A 360 6 TDS 340A ...
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Page 248: ...DISPLAY A11 A12 TDS 340A 360 7 ...
Page 252: ...MAIN BLOCK DIAGRAM A13 TDS 380 0 MAIN BOARD 671 3753 00 389 2154 00 ...
Page 253: ......
Page 254: ...TRIGGERS A13 TDS 380 1 ...
Page 255: ......
Page 256: ...ATTENUATORS A13 TDS 380 2 ...
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Page 258: ...TRIGGER LOGIC AND TIME INTERPOLATOR A13 TDS 380 3 ...
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Page 260: ...TIMEBASE A13 TDS 380 4 ...
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Page 262: ...SAMPLER A13 TDS 380 5 ...
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Page 264: ...CPU A13 TDS 380 6 ...
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Page 266: ...DISPLAY A13 TDS 380 7 ...
Page 269: ...9 62 TDS 340A TDS 360 TDS 380 Technical Reference ...
Page 270: ...MONITOR BLOCK DIAGRAM A26 TDS 340A 360 380 0 ...
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Page 272: ...INPUTS VIDEO AND VERTICAL DEFLECTION A26 TDS 340A 360 380 1 ...
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Page 286: ...Mechanical Parts List 10 12 TDS 340A TDS 360 TDS 380 Technical Reference ...
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