Options— 2230 Service
Table 7-36
RS-232-C Status Buffer Functions
Bit
Signal Name
Function
Bit 0
PWR INT
Power-going-down interrupt
Bit 1
DR + INTR
UART interrupt request
Bit 2
TBRE
UART interrupt request
Bit 3
Parameter switch position 8
Bit 4
Parameter switch position 10
Bit5
Parameter switch position 9
Bit 6
DIAG
Interrupt mask latch D3
Bit 7 |
DCD2
Data carrier detect
OPTION MEMORY
Option Memory (see Diagram 25) contains 32K-bytes of
non-volatile memory, a lithium battery, and power failure
sensing and control circuitry. When the board is installed,
the option RAM is disabled.
Address Decoding
Addresses are decoded by U1162. All addresses in the
COM-SEG range (88000-8FFFF) are used. Four active LO
strobes, one for each RAM, are generated, DECODE 0
(U1162 pin 4), DECODE 1 (U1162 pin 5), DECODE 2
(U1162 pin 12), and DECODE 3 (U1162 pin 11).
RAM
Four 8K-byte RAMs make up the 32K-byte non-volatile
memory. When instrument power is turned off, STANDBY
goes LO, placing the memories in a low current standby
state. In the standby state the lithium battery (BT1101)
supplies the memories standby current needs.
Each RAM is selected by its Decode signal (pin 20)
when the memories are not in standby. Data is read onto
the data bus, BD1-BD7, from the memory location
selected by BA0-BA12 when BRD goes LO. Data on the
data bus, BD0-BD7, is written to the memory location
selected by BA0-BA12 when BWR goes LO.
Power Sense
Power to the RAM array is supplied by the Power
Sense circuitry. The Power Sense circuit supplies power to
the RAM either from the instrument power supply or from
the lithium battery.
W A R N I N G
The battery used in this device may present a fire or
chemical burn hazard if mistreated. Do not recharge,
rapidly discharge, disassemble, heat, or short termi
nals.
See
service
information
for complete
instructions.
Lithium Battery
If instrument power is available, 5 V from the instru
ment forward biases CR1102 and reverse biases CR1104,
disconnecting lithium battery BT1101 from the circuit.
Because CR1102 is forward biased, the instrument suplies
power (+ V S) to the RAM through CR1102.
If instrument power is not available, the lithium battery
forward biases CR1104 and reverse biases CR1102, sup
plying power (+ V S) to the RAM through CR1104. If there
is a circuit failure, lithium battery current is limited to safe
levels by ceramic current limiter RT1102.
Voltage Comparator
U1122 compares the instrument voltage to an internal
reference to determine if the power is going down. If
power is going down, an interrupt is generated to tell the
Microprocessor that the power is failing. Also, the RAM is
put in standby.
Comparator U1122 compares its internal reference to
the voltage on pin 3. The voltage at U1122 pin 3 is set by
the instrument power supply and the voltage divider made
up of R1112, R1114, and R1116.
If power is up, the voltage at pin 3 is about 1.2 V, and
FAIL at U1122 pin 4 is LO. FAIL is inverted and delayed
by U1132B, C, D, and associated circuitry, making
STANDBY normal operating mode. Also, FAIL is inverted
and delayed by U1132B and associated circuitry, generat
ing FAIL HI. Comparators U1142A and U1142B look at
both the instrument supply voltage and FAIL. If FAIL goes
HI (power is coming up), interrupts are not generated, but
U1132D pulses the IRST signal HI to reset the micropro
cessor systems.
If power is going down or is down, the voltage at
U1122 pin 3 drops below the internal reference voltage,
causing FAIL, U1122 pin 4 to go HI. FAIL is inverted and
delayed by U1132B and associated circuitry, generating
FAIL LO. Comparators U1142A and U1142B look at both
the instrument supply voltage and FAIL. Since FAIL is LO
7 -4 3
Summary of Contents for 2230
Page 12: ...2230 Service X The 2230 Digital Storage Oscilloscope 4998 01 ...
Page 33: ...Operating Information 2230 Service Figure 2 5 Vertical controls and connectors 2 6 ...
Page 48: ...Operating Information 2230 Service Figure 2 11 X Y Plotter interfacing ...
Page 56: ...Theory of Operation 2230 Service 4999 01 3 2 Figure 3 1 Simplified block diagram ...
Page 68: ...Operating Information 2230 Service Figure 2 11 X Y Plotter interfacing ...
Page 76: ...Theory of Operation 2230 Service 4999 01 3 2 Figure 3 1 Simplified block diagram ...
Page 98: ...Theory of Operation 2230 Service 499 9 06 Figure 3 6 Horizontal Amplifier block diagram 3 24 ...
Page 111: ...Theory of Operation 2230 Service 3 37 Figure 3 9 Acquisition Memory timing ...
Page 190: ...Maintenance 2230 Service 999 14 Figure 6 3 Isolated kernel timing 6 9 ...
Page 329: ...PUT Figure 9 2 S em ico n d u cto r lea d co n fig u ratio n s ...
Page 332: ...2230Service CHASSIS MOUNTED PARTS ...
Page 334: ...A14 CH 1 LOGIC BOARD ...
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Page 344: ...u sr z z o 1 ...
Page 347: ...i n 5 a O Q q o u S a o h UJ s a b c d e f g h j k l m n ...
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Page 355: ...WAVEFORMS FOR DIAGRAM 5 4999 83 ...
Page 358: ...I W L U O U rc a 4 2 s ...
Page 361: ...WAVEFORMS FOR DIAGRAM 6 S 84 ...
Page 362: ...2230 Service TEST SCOPE TRIGGERED ON U665 PIN 8 FOR WAVEFORMS 31 THROUGH 33 ...
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Page 366: ...A 1 6 S W E E P R EFEREN CE BOARD FIG 9 17 2230 Service Figure 9 17 A16 Sweep Reference board ...
Page 369: ... o 0 UJU sa eg aiu c u J in su eg 5 C sis n g e s o N QO ...
Page 371: ...Static Sensitive Devices See Maintenance Section CM I rv CD o 2230 Service ...
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Page 388: ...H K L M N 7 8 8 2 2 3 0 INPUT OUTFUT WIRING INTERCONNECT ...
Page 392: ...W A V E F O R M S F O R D IA G R A M 14 ...
Page 393: ...2230Service 0 0 d s t 4 9 9 9 9 5 ...
Page 394: ...2230 Service TEST SCOPE TRIGGERED ON U911 PIN 21 FOR WAVEFORMS 64 THROUGH 69 4999 92 ...
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Page 397: ...WAVEFORMS FOR DIAGRAM 15 TEST SCOPE TRIGGERED ON U9111 PIN 21 FOR WAVEFORMS 70 THROUGH 77 ...
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Page 423: ...W A V E F O R M SF O RD IA G R A M1 8 O c n ...
Page 424: ...Figure 9 22 A11A1 Input Output board ...
Page 430: ...Figure 9 23 A11A2 Vector Generator board ...
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Page 437: ...22 3 0 S ervice W A V E F O R M S F O R D I A G R A M 2 1 m f n h ...
Page 442: ...WAVEFORMS FOR DIAGRAM 22 4999 78 ...
Page 443: ...XY PLOTTER BOARD DIAGRAM 22 See Parts List for serial number ranges ...
Page 447: ...A21 RS 232 OPTION BOARD Flfi A 9 K 01 01 W M ...
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Page 452: ...COMPONENT NUMBER EXAMPLE ...
Page 459: ...A16 SWEEP REFERENCE ADJUSTMENT LOCATION ...
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