Tektronix WFM601, Руководство по обслуживанию

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Theory of Operation
WFM 601 - Service Manual
3–9
Digital Half-Band Filters on Diagrams 5 and 6. The Y Time signal is one of the
inputs to the Clock PAL on Diagram 4, which selects the correct Y signal for the
color difference signals through the DACs. If incorrect Y is used there will be a
color phase shift apparent in the RGB output.
Control and interrogation of the Coprocessor is over data and address buses
shared with the Component circuit board (Diagram 10). The buses connect
through J2. The Coprocessor uses 8 bits (BD8 - BD15) of the data bus and 6
bits (BA0 - BA5) of the address bus. The address bus controls which internal
input and output registers are being read or written to. In addition, there is an
enable bit, BA15, that is high for the Coprocessor and low for the Component
board.
There are five Coprocessor outputs that communicate directly with the Compo-
nent circuit board.
COMPSYNC - Provides the composite sync signal used by the Component
circuitry.
BLANK - An active low signal that controls switches that control the input
levels to the Component Amplifiers during the vertical interval.
CLAMP PLS - An active low signal that controls when clamping of the
Component Amplifiers occurs.
GAMUT ERR - Goes low when a gamut error is being detected on the
Component circuit board. Error data is read out to the Microprocessor over
data bits BD8 - BD15.
GAMUT INH - Turns off the flashing display, on the Monitor Out signal,
when a gamut error is occuring.
CSPARES - Not used.
This function is not used in the WFM 601 current applications.
The Serial PROM is used to initialize the Coprocessor. When Power is applied
the RESET line goes high, which automatically tells the Coprocessor to read the
Serial PROM for its initial configuration. The Coprocessor generates a Clock
signal for the Serial PROM, which begins to output the configuration data
(CONFIG D) to the Coprocessor. When all the necessary configuration data is
received the Coprocessor generates CONFIG DONE to disable the Serial PROM
output.
Line Buffer RAM
Serial PROM