Application Specific Extension

The MCU ASE (Application Specific Extension) has been developed to extend the interrupt controller support, reduce the interrupt latency and enhance the I/O peripheral control function typically required in microcontroller system designs. It is implemented on the MIPS32® M14K™ family of processor cores.

The MCU ASE supports both MIPS32 and microMIPSTM Instruction Set Architectures (ISAs).

Interrupt Delivery

  • Separate priority and vector generation
  • Supports up to 256 interrupts in EIC (External Interrupt Controller) mode and 8 hardware interrupt pins
  • Provides 16-bit vector offset address



I/O Peripheral Control

Includes atomic bit set/clear instructions which enables bits within an I/O register that are normally used to monitor or control external peripheral functions to be modified without interruption, ensuring the action is performed securely.

Reduced Interrupt Latency



  • Pre-fetching of the interrupt exception vector
  • Automated Interrupt Prologue – adds hardware to save and update system status before the interrupt handling routine
  • Automated Interrupt Epilogue – restores the system state previously stored in the stack for returning from the interrupt.
  • Interrupt Chaining – supports the service of pending interrupts without the need to exit the initial interrupt routine, saving the cycles required to store and restore multiple active interrupts
  • Supports speculative pre-fetching of the interrupt vector address. Reduces the number of interrupt service cycles by overlapping memory accesses with pipeline flushes and exception prioritization


MIPS Architecture for Programmers