Xerox 560 Reference Manual

Table 3. Summary of Trap Locations
Locations
PSWs
Dec. Hex.
Function
Mask Bit
Time
of Occurrence Trap Condi ti on Code
64
40
Nonallowed operation
l.
Nonexistent None
At instruction decode.
Set TCC1 t
instruction
2. Nonexistent mem- None
Prior to memory access. Set TCC2
ory address
3.
Privi leged instruc- None
At instruction decode. Set TCC3
tion in slave mode
4. Memory protection
None
Prior to memory access.
Set TCC4
violation
5.
Write lock violation None
Prior to memory access.
Set TCC3,
TCC4
65
41
Reserved
66
42
Push-down stack limit TW, TS
At the time of stack limit detection.
None
reached
(in stack (The aborted pushdown instruction
pointer) does not
change memory, registers,
or the condition
code.)
67
43
Fixed-point arithmetic
AM
For
all instructions except DWand None
overflow
DH, trap occurs after completion of
instruction.
For
DW and DH, instruc-
tion is aborted with memory, register,
CC1, CC3, and CC4 unchanged.
68
44 Floating-point arithme- At detection.
tic fault
1.
Characteristic None
{(The floating-point instruction is
None
overflow
aborted without changing any reg-
2. Divide by zero None
isters. The
condition code is set to
None
3. Significance check FS, FZ, FI\
indicate the reason for the trap.)
None
69 45 Decimal arithmetic fault
DM
At detection. (The aborted decima I
None
instruction does not
change memory,
registers,
CC3, or CC4.)
70 46 Watchdog timer runout None At runout. (The PDF
tt
flag will be Set TCC2 if basic pro-
set.) cessor usi ng processor
bus;
set TCC3 if basic pro-
cessor us i ng memory
bus; and
set TCC4 if basic pro-
cessor using DIO bus.
71 47
Programmed trap
None Interruptible point reached upon
None
completion
of WD.
tSee "Trap Condition
Code
ll
, later in this chapter.
tt See II Processor Detected Fau I ts ", la ter in th i s cha pter .
T rap System 37

Xerox 560 Specifications

General

Brand	Xerox
Model	560
Category	Printer
Language	English