Patent ID: 6917997
Filing Date: 2005-07-12
Classification: G06F

Abstract:
1. A single integrated circuit (IC), comprising: a synthesizable ARM-type microcontroller processor core connected to a program code memory that selectively processes either a THUMB or an ARM program execution stream, wherein said THUMB program execution stream is more economical with program code space, and wherein a program-execution interrupt request forces a hardware switch to said ARM program execution stream; an interrupt controller that receives interrupt requests and provides a programmable combination of said interrupt requests to the core, wherein each said interrupt request is associated with one of a plurality of interrupt service routines coded in THUMB program code; and an interrupt service routine preamble shared amongst said plurality of interrupt service routines, said interrupt service routine preamble is coded in ARM program code to cause a switch to THUMB program execution, said interrupt controller causes the execution of said interrupt service routine preamble before an interrupt service routine is executed.