HP 3000 III Series Manual page 109

System Verification and Troubleshooting
Table 3-2. Maintenance Panel Switches and Lamps (Continued)
I---'---'---~r----------~-----'-~---~--I--
- -----_. .
- -----_._._--~-
-. . .
- --~
. .
- -~--._------~---------
I
Panel
I
Panel Marking
I
Use
I
Row
I I
I I I
1-----
_.~--
------.-
--~----._.--- ---~----~--_.----.--.------------------
I
4 CPU TIMER Indicates that a module did not respond
(lamp) to the CPU within a specified time.
Indicates the CPU is waiting for an in-
struction from memory.
Indicates the CPU is waiting for an op-
erand from memory.
Indicates a multiplexed I/O operation is
fetching a word from memory.
Lighted when a microprogram halt is in
effect or when the V-Bus carries the
same number as the V BUS COMPARE REGIST-
E R
s wi tche s •
4
OPND WAI'!'
(lamp)
4
INSTR WAIT
( lamp)
4 I/O WAIT
( lamp)
4 PANEL FREEZ E
( lamp)
4
FREEZE ( lamp)
5
ICS FLAG
( lamp)
5
DISP FLAG
(lamp)
5 C MUX (lamp)
Indicates the CPU freezable clock has
stopped.
Indicates the Interrupt Stack Flag flip-
flop is set.
Indicates the dispatcher is executing.
Indicates which instruction is being de-
coded. Lighted = current instruction;
off
=
next instruction.
5
NEXT +
I
( lamp)
Indicates the sequence is in the "next
sequence" s ta te •
5 INTRPT FF
( lamp)
Indicates the state of the Interrupt
flip-flop. When lighted, an external or
internal interrupt is pending.
5
5
JSB FLAG
(lamp)
NOP (lamp)
Indicates the microcode is executing a
sUbroutine.
Indicates one of the normal inputs of
the V-Bus are turned off caused by any
one of the follow ing:
CPU Reset
PWR ON
UGATE on (RAR in the Store Field)
3-9