Agilent Technologies 35670A Service Manual page 357

BASn
MD24 — MD31
NVPRESn
OPRAMn
PA0 — PA21
PROTCTn
PRW
VBATT
Agilent 35670A
Signal Name
PROTCTn
PA18
PA19
PA20
PA21
PRW
VBATT
+5
Gnd
S This assembly is the source of the signal.
• This assembly uses the signal.
⇔ This signal is bidirectional.
— This assembly does not use this signal.
Buffered Address Strobe — This line pulses low when a valid address is on the processor
address bus (PA0 — PA21).
Memory Data Bus — This is the buffered processor data bus from the A7 CPU assembly. This
bus is further buffered on the A8 Memory assembly.
NRAM Present — A low on this line indicates that the A9 NVRAM assembly is connected to
the A8 Memory assembly. This line is checked only during manual troubleshooting
procedures.
Optional RAM — A low on this line enables the battery-backed static RAM on the
A9 NVRAM assembly.
Processor Address Bus — This is the processor address bus from the A7 CPU assembly. This
bus is buffered on the A8 Memory assembly.
Protect — A low on this line disables the battery-backed static RAM on the A9 NVRAM
assembly. This line pulses low during power-up and power-down, when the A7 CPU
assembly's microprocessor is externally reset, and when +5 volts on the A8 Memory assembly
is too low.
Processor Read/Write — This line is high when the current memory cycle is a read and low
when the current memory cycle is a write.
Battery Voltage — This line provides the power to the battery-backed static RAM on the
A9 NVRAM assembly. When the analyzer is on, the +5 volts on the A8 Memory assembly
provides the power for this line. When the analyzer is off, the battery on the Memory assembly
provides the power for this line. Since power is applied to the static RAM even when the
analyzer is off, the static RAM is non-volatile.
Pin(s)
A9
C16
A4
A12
B16
A3
A13, A14, A15
A10, A11, B11, C11
A1, A5, B5, C5, A7, A8
Voltages and Signals
A8 P2 A9 J1
S
S
S
S
S
•
S
•
•
A9 NVRAM
•
•
•
•
•
•
•
•
•
9-13