XC164LM_07 datasheet(21/61 Pages) INFINEON

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XC164LM

Derivatives

Functional Description

Data Sheet

V1.2, 2007-03

3.3

Interrupt System

With an interrupt response time of typically 8 CPU clocks (in case of internal program

execution), the XC164LM is capable of reacting very fast to the occurrence of non-

deterministic events.

The architecture of the XC164LM supports several mechanisms for fast and flexible

response to service requests that can be generated from various sources internal or

external to the microcontroller. Any of these interrupt requests can be programmed to

being serviced by the Interrupt Controller or by the Peripheral Event Controller (PEC).

In contrast to a standard interrupt service where the current program execution is

suspended and a branch to the interrupt vector table is performed, just one cycle is

‘stolen’ from the current CPU activity to perform a PEC service. A PEC service implies a

single byte or word data transfer between any two memory locations with an additional

increment of either the PEC source, or the destination pointer, or both. An individual PEC

transfer counter is implicitly decremented for each PEC service except when performing

in the continuous transfer mode. When this counter reaches zero, a standard interrupt is

performed to the corresponding source related vector location. PEC services are very

well suited, for example, for supporting the transmission or reception of blocks of data.

The XC164LM has 8 PEC channels each of which offers such fast interrupt-driven data

transfer capabilities.

A separate control register which contains an interrupt request flag, an interrupt enable

flag and an interrupt priority bit field exists for each of the possible interrupt nodes. Via

its related register, each node can be programmed to one of sixteen interrupt priority

levels. Once having been accepted by the CPU, an interrupt service can only be

interrupted by a higher prioritized service request. For the standard interrupt processing,

each of the possible interrupt nodes has a dedicated vector location.

Fast external interrupt inputs are provided to service external interrupts with high

precision requirements. These fast interrupt inputs feature programmable edge

detection (rising edge, falling edge, or both edges).

Software interrupts are supported by means of the ‘TRAP’ instruction in combination with

an individual trap (interrupt) number.

Table 4 shows all of the possible XC164LM interrupt sources and the corresponding

hardware-related interrupt flags, vectors, vector locations and trap (interrupt) numbers.

Note: Interrupt nodes which are not assigned to peripherals (unassigned nodes), may

be used to generate software controlled interrupt requests by setting the

respective interrupt request bit (xIR).

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