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TM 11-6625-3145-14
Maintenance: Troubleshooting-318/338 Service
Table 7-4
318 CLOCK TEST PROGRAM RANGES
Gate Clock
SYSCLK
SLOW CLOCK flag
1 ms
20 ns
reset
50 ns
reset
100
µ
s
reset
1 ms
set
200
µ
s
reset
2 ms
set
50
µ
s
reset
5 ms
set
10 ms
500
µ
s
reset
10 ms
set
The INTCLK signal is generated by the timebase circuit, U140, which counts 10 ns clock pulses to produce a range
of timebase signals ranging from 20 ns to 500 ms. The INTCLK signal is buffered by U112 (quad 2-input NOR gate,
MC1662) on the A04 board. This signal is sent to U222 on the A02 board through the A08 Mother board. The
output of U222 is returned to the SYSCLK input of U140 on the A04 board via the A08 board.
U 158 (event/delay counter, uPD3Z198R) on the A03 ACQ Control board generates the interrupt to the MPU when it
receives the timer signal from U 140 on the A04 board. This interrupt is sent to the MPU as INT via U156
(comparator with open collector output,
µ
PD311C) and via the A08 board.
The MPU reads the status by issuing READ STATUS at I/O address 5D
hex
through U152 (octal buffer/line driver with
tri-state output, 74LS244). U152 is enabled by OE from U126 (quad 2-input NOR gate, 10102). The status from
U140 is selected by U144 (quad 2-input multiplexer, 10158) on the A04 board and is converted from ECL to TTL
level. Then it is fed to U152 on the A04 board for the MPU. The MPU compares the slow clock flag with the
expected value (see Table 7-4), and displays an error message if it does not match.
7-12
Summary of Contents for 318
Page 119: ...318 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 182: ...338 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 253: ...318 ___________________ TROUBLESHOOTING TREES ...
Page 344: ...338 TROUBLESHOOTING TREES ...
Page 517: ...TM 11 6625 3145 14 318 338 4434 923 318 Block Diagram ...
Page 518: ...TM 11 6625 3145 14 318 338 4434 924 338 Block Diagram ...
Page 519: ...TM 11 6625 3145 14 318 338 4434 925 318 Acquisition Module Wiring Diagram ...
Page 520: ...TM 11 6625 3145 14 318 338 4434 926 318 338 Mainframe Wiring Diagram ...
Page 521: ...TM 11 6625 3145 14 318 338 4434 926 338 Acquisition Module Wiring Diagram ...
Page 522: ...TM 11 6625 3145 14 318 338 4434 928 Figure 9 1 318 A01 Input A Board Component Locations ...
Page 526: ...TM 11 6625 3145 14 ...
Page 528: ...TM 11 6625 3145 14 Figure 9 3 318 338 A03 ACQ Control Board Component Locations ...
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Page 538: ...TM 11 6625 3145 14 ...
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Page 542: ...TM 11 6625 3145 14 Figure 9 8 318 338 A10 CRT Board Component Locations ...
Page 544: ...TM 11 6625 3145 14 Figure 9 9 318 338 A11 Inverter Board component Locations ...
Page 546: ...TM 11 6625 3145 14 Figure 9 10 318 338 A12 Regulator Board Component Locations ...
Page 551: ...TM 11 6625 3145 14 Figure 9 12 338 A01 Input A Board Component Locations ...
Page 553: ...TM 11 6625 3145 14 318 338 SERVICE ...
Page 554: ......
Page 555: ...PIN 058584 ...