PSB21473FV13XT Infineon Technologies, PSB21473FV13XT Datasheet - Page 65

• 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

Bit
sp
The Stack Overflow Pointer STKOV
This non-bit addressable register is compared against the SP register after each
operation, which pushes data onto the system stack (eg. PUSH and CALL instructions
or interrupts) and after each subtraction from the SP register. If the content of the SP
register is less than the content of the STKOV register, a stack overflow hardware trap
will occur.
Since the least significant bit of register STKOV is tied to '0' and bits 15 through 12 are
tied to '1' by hardware, the STKOV register can only contain values from F000
FFFE
STKOV (FE14
Bit
stkov
The Stack Overflow Trap (entered when (SP) < (STKOV)) may be used in two different
ways:
• Fatal error indication treats the stack overflow as a system error through the
associated trap service routine. Under these circumstances data in the bottom of the
stack may have been overwritten by the status information stacked upon servicing the
stack overflow trap.
• Automatic system stack flushing allows to use the system stack as a 'Stack Cache'
for a bigger external user stack. In this case register STKOV should be initialized to a
value, which represents the desired lowest Top of Stack address plus 12 according to
the selected maximum stack size. This considers the worst case that will occur, when a
stack overflow condition is detected just during entry into an interrupt service routine.
Then, six additional stack word locations are required to push IP, PSW, and CSP for both
the interrupt service routine and the hardware trap service routine.
More details about the stack overflow trap service routine and virtual stack management
are given in chapter “System Programming”.
Data Sheet
15
r
1
H
14
r
.
1
13
r
1
H
/ 0A
Function
Modifiable portion of register SP
Specifies the top of the internal system stack.
Function
Modifiable portion of register STKOV
Specifies the lower limit of the internal system stack.
12
r
1
H
)
11
10
9
8
SFR
65
7
stkov
6
rw
5
4
Central Processor Unit
3
Reset Value: FA00
2
PSB 21473
1
2003-03-31
INCA-D
0
r
0
H
H
to