SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 123

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

TFR
Trap Flag Register
Bit
ILLBUS
ILLINA
ILLOPA
PRTFLT
UNDOPC
STKUF
STKOF
NMI
Note: The trap service routine must clear the respective trap flag; otherwise, a new trap
In the case where e.g. an Undefined Opcode trap (class B) occurs simultaneously with
an NMI trap (class A), both the NMI and the UNDOPC flag is set, the IP of the instruction
with the undefined opcode is pushed onto the system stack, but the NMI trap is executed.
After return from the NMI service routine, the IP is popped from the stack and
immediately pushed again because of the pending UNDOPC trap.
User’s Manual
NMI STK
rwh
15
will be requested after exiting the service routine. Setting a trap request flag by
software causes the same effects as if it had been set by hardware.
rwh
OF
14
STK
rwh
UF
13
Function
Illegal External Bus Access Flag
An external access has been attempted with no external bus defined.
Illegal Instruction Access Flag
A branch to an odd address has been attempted.
Illegal Word Operand Access Flag
A word operand access (read or write) to an odd address has been
attempted.
Protection Fault Flag
A protected instruction with an illegal format has been detected.
Undefined Opcode Flag
The currently decoded instruction has no valid C164CM opcode.
Stack Underflow Flag
The current stack pointer value exceeds the content of register STKUN.
Stack Overflow Flag
The current stack pointer value falls below the content of reg. STKOV.
Non Maskable Interrupt Flag
A negative transition (falling edge) has been detected on pin NMI.
12
-
11
-
-
10
-
-
SFR (FFAC
9
-
-
8
-
-
5-33
UND
OPC
rwh
7
H
/D6
H
6
-
-
)
Interrupt and Trap Functions
5
-
-
4
-
-
PRT
FLT
rwh
Reset Value: 0000
C164CM/C164SM
3
OPA
rwh
ILL
2
Derivatives
V1.0, 2002-02
INA
rwh
ILL
1
BUS
rwh
ILL
0
H