SAF-C161U-LF V1.3 Infineon Technologies, SAF-C161U-LF V1.3 Datasheet - Page 105

• 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

C161U
Interrupt and Trap Functions
7
Interrupt and Trap Functions
The architecture of the C161U supports several mechanisms for fast and flexible
response to service requests that can be generated from various sources internal or
external to the microcontroller. These mechanisms include:
Normal Interrupt Processing
The CPU temporarily suspends the current program execution and branches to an
interrupt service routine in order to service an interrupt requesting device. The current
program status (IP, PSW, in segmentation mode also CSP) is saved on the internal
system stack. A prioritization scheme with 16 priority levels allows the user to specify the
order in which multiple interrupt requests are to be handled.
Interrupt Processing via the Peripheral Event Controller (PEC)
A faster alternative to normal software controlled interrupt processing is servicing an
interrupt requesting device with the C161U's integrated Peripheral Event Controller
(PEC). Triggered by an interrupt request, the PEC performs a single word or byte data
transfer between any two locations in segment 0 (data pages 0 through 3) through one
of eight programmable PEC Service Channels. During a PEC transfer the normal
program execution of the CPU is halted for just 1 instruction cycle. No internal program
status information needs to be saved. The same prioritization scheme is used for PEC
service as for normal interrupt processing. PEC transfers share the 2 highest priority
levels.
Trap Functions
Trap functions are activated in response to special conditions that occur during the
execution of instructions. A trap can also be caused externally by the Non-Maskable
Interrupt pin NMI. Several hardware trap functions are provided for handling erroneous
conditions and exceptions that arise during the execution of an instruction. Hardware
traps always have highest priority and cause immediate system reaction. The software
trap function is invoked by the TRAP instruction, which generates a software interrupt for
a specified interrupt vector. For all types of traps the current program status is saved on
the system stack.
External Interrupt Processing
Although the C161U does not provide dedicated interrupt pins, it allows to connect
external interrupt sources and provides several mechanisms to react on external events,
including standard inputs, non-maskable interrupts and fast external interrupts. These
interrupt functions are alternate port functions, except for the non-maskable interrupt and
the reset input.
Data Sheet
105
2001-04-19