SAF-C161U-LF V1.3 Infineon Technologies, SAF-C161U-LF V1.3 Datasheet - Page 81

• Manufacturer Part Number: SAF-C161U-LF V1.3
• Description: IC MCU ISDN 16BIT TTL TQFP-100
• Manufacturer: Infineon Technologies
• Series: C16xxr

Specifications of SAF-C161U-LF V1.3

• Core Processor: C166
• Core Size: 16-Bit
• Speed: 36MHz
• Connectivity: EBI/EMI, SPI, UART/USART, USB
• Peripherals: POR, PWM, WDT
• Number Of I /o: 56
• Program Memory Type: ROMless
• Ram Size: 3K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -
• Other names: SAFC161ULFV1.3X; SAFC161ULFV13XP; SP000007502

More details about the stack overflow trap service routine and virtual stack management
are given in chapter “System Programming”.
Stack Underflow Pointer STKUN
This non-bit addressable register is compared against the SP register after each
operation, which pops data from the system stack (eg. POP and RET instructions) and
after each addition to the SP register. If the content of the SP register is greater than the
the content of the STKUN register, a stack underflow hardware trap will occur.
Since the least significant bit of register STKUN is tied to '0' and bits 15 through 12 are
tied to '1' by hardware, the STKUN register can only contain values from F000
FFFE
STKUN (FE16
The Stack Underflow Trap (entered when (SP) > (STKUN)) may be used in two different
ways:
• Fatal error indication treats the stack underflow as a system error through the
• Automatic system stack refilling allows to use the system stack as a 'Stack Cache'
More details about the stack underflow trap service routine and virtual stack
management are given in chapter “System Programming”.
Scope of Stack Limit Control
The stack limit control realized by the register pair STKOV and STKUN detects cases
where the stack pointer SP is moved outside the defined stack area either by ADD or
SUB instructions or by PUSH or POP operations (explicit or implicit, ie. CALL or RET
instructions).
Data Sheet
Bit
stkun
15
1
r
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.
associated trap service routine.
for a bigger external user stack. In this case register STKUN should be initialized to a
value, which represents the desired highest Bottom of Stack address.
H
.
14
1
r
13
H
1
r
/ 0B
Function
Modifiable portion of register STKUN
Specifies the upper limit of the internal system stack.
12
H
1
r
)
11
10
9
8
SFR
81
7
stkun
rw
6
5
4
Central Processor Unit
Reset Value: FC00
3
2
2001-04-19
1
C161U
0
0
r
H
H
to