PSB21473FV13XT Infineon Technologies, PSB21473FV13XT Datasheet - Page 121

• Manufacturer Part Number: PSB21473FV13XT
• Manufacturer: Infineon Technologies

Specifications of PSB21473FV13XT

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3.135V
• Operating Supply Voltage (max): 3.6V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 144
• Lead Free Status / RoHS Status: Compliant

INCA-D
PSB 21473
Interrupts
A class A trap occurring during the execution of a class B trap service routine will be
serviced immediately. During the execution of a class A trap service routine, however,
any class B trap occurring will not be serviced until the class A trap service routine is
exited with a RETI instruction. In this case, the occurrence of the class B trap condition
is stored in the TFR register, but the IP value of the instruction which caused this trap is
lost.
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.
External NMI Trap
Whenever a high to low transition on the dedicated external NMI pin (Non-Maskable
Interrupt) is detected, the NMI flag in register TFR is set and the CPU will enter the NMI
trap routine. The IP value pushed on the system stack is the address of the instruction
following the one after which normal processing was interrupted by the NMI trap.
Stack Overflow Trap
Whenever the stack pointer is decremented to a value which is less than the value in the
stack overflow register STKOV, the STKOF flag in register TFR is set and the CPU will
enter the stack overflow trap routine. Which IP value will be pushed onto the system
stack depends on which operation caused the decrement of the SP. When an implicit
decrement of the SP is made through a PUSH or CALL instruction, or upon interrupt or
trap entry, the IP value pushed is the address of the following instruction. When the SP
is decremented by a subtract instruction, the IP value pushed represents the address of
the instruction after the instruction following the subtract instruction.
For recovery from stack overflow it must be ensured that there is enough excess space
on the stack for saving the current system state (PSW, IP, in segmented mode also CSP)
twice. Otherwise, a system reset should be generated.
Stack Underflow Trap
Whenever the stack pointer is incremented to a value which is greater than the value in
the stack underflow register STKUN, the STKUF flag is set in register TFR and the CPU
will enter the stack underflow trap routine. Again, which IP value will be pushed onto the
system stack depends on which operation caused the increment of the SP. When an
implicit increment of the SP is made through a POP or return instruction, the IP value
pushed is the address of the following instruction. When the SP is incremented by an
add instruction, the pushed IP value represents the address of the instruction after the
instruction following the add instruction.
Data Sheet
121
2003-03-31