SAB80C166-M-T3 SIEMENS [Siemens Semiconductor Group], SAB80C166-M-T3 Datasheet - Page 15

• Manufacturer Part Number: SAB80C166-M-T3
• Description: 16-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

The SAB 80C166 also provides an excellent mechanism to identify and to process exceptions or
error conditions that arise during run-time, so-called ‘Hardware Traps’. Hardware traps cause
immediate non-maskable system reaction which is similar to a standard interrupt service (branching
to a dedicated vector table location). The occurrence of a hardware trap is additionally signified by
an individual bit in the trap flag register (TFR). Except when another higher prioritized trap service
is in progress, a hardware trap will interrupt any actual program execution. In turn, hardware trap
services can normally not be interrupted by standard or PEC interrupts.
The following table shows all of the possible exceptions or error conditions that can arise during run-
time:
Exception Condition
Reset Functions:
Class A Hardware Traps:
Class B Hardware Traps:
Reserved
Software Traps
Semiconductor Group
Hardware Reset
Software Reset
Watchdog Timer Overflow
Non-Maskable Interrupt
Stack Overflow
Stack Underflow
Undefined Opcode
Protected Instruction
Fault
Illegal Word Operand
Access
Illegal Instruction Access
Illegal External Bus
Access
TRAP Instruction
Trap
Flag
NMI
STKOF
STKUF
UNDOPC
PRTFLT
ILLOPA
ILLINA
ILLBUS
Trap
Vector
RESET
RESET
RESET
NMITRAP
STOTRAP
STUTRAP
BTRAP
BTRAP
BTRAP
BTRAP
BTRAP
14
Vector
Location
0000
0000
0000
0008
0010
0018
0028
0028
0028
0028
0028
[002C
003C
Any
[0000
01FC
in steps
of 04
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
]
]
–
–
SAB 80C166/83C166
Trap
Number
00
00
00
02
04
06
0A
0A
0A
0A
0A
[0B
Any
[00
H
H
H
H
H
H
H
H
H
H
H
H
H
– 7F
– 0F
H
H
]
]
Trap
Priority
III
III
III
II
II
II
I
I
I
I
I
Current
CPU
Priority