HP 3000 SERIES II System Service Manual page 67

ICS DISP
FLAG FLAG
o
0
C NEXT INTRPT JSB
MUX +1 FF FLAG NOP
o
0 0 0 0
Maintenance Panel Operating Procedures
LUT INTRPT U RAR SAVE JUMP 1 JUMP 2 JUMP
BNDV GATE GATE GATE GATE GATE GATE GATE FREEZE
o
0 0 0 0 0 0 0 0
I
Table 3-1. Maintenance Panel Controls and Indicators (Continued)
PANEL
ROW
PANEL MARKING
5 ICS FLAG (lamp)
5 DISP FLAG (lamp)
5 C MUX (lamp)
5 NEXT
+
1 (lamp)
5 INTRPT FF (lamp)
5
JSB FLAG (lamp)
5
NOP (lamp)
USE
Indicates the interrupt stack flag FF is set.
Indicates the dispatcher is executing.
Indicates which instruction is being decoded. Lighted
=
current
instruction, off
=
next instruction.
Indicates the sequence is in the "next sequence" state.
Indicates the state of the interrupt FF. When lighted, an external or
internal interrupt is pending.
Indicates the microcode is executing a subroutine.
Indicates one of the normal inputs of the V Bus are turned off
caused by anyone of the following:
• CPU Reset
• PWR ON
• UGATE on (RAR in the Store Field)
• INTG on (A CPU interrupt is forcing the V Bus to address 3).
• The execution of a V Bus jump with panel switches
5
5
5
5
5
5
5
5
5
BNDV (lamp)
LUT GATE (lamp)
INTRPT GATE (lamp)
U GATE (lamp)
RAR GATE (lamp)
SAVE GATE (lamp)
JUMP 1 GATE (lamp)
JUMP 2 GATE (lamp)
JUMP FREEZE (lamp)
Indicates a memory instruction references an address outside the
limit registers.
Indicates an instruction target address is being sent to the V Bus.
Indicates when doing a NEXT
+
1 cycle and a microcode interrupt
is pending or when a bounds violation has been detected.
Indicates the U Bus is gated onto the V Bus.
Indicates the current address
+
1 is put on the V Bus.
Indicates the microcode return address is being gated onto the
V Bus.
Indicates the jump target from Rank 1 is being gated onto the V
Bus.
Indicates the jump target from Rank 2 is being gated onto the V
Bus.
Indicates a one cycle freeze is taking place to allow a new V Bus
address.
3-5