Exception handling involving emulation of exception triggering data transfer operation using syndrome data store that includes data value to be transferred

Apparatus for processing data comprising:

• a plurality of register means for storing data;
• exception handling means for detecting attempted execution of an exception-triggering processing operation including a transfer of a data value with a given register means of said plurality of register means and for triggering execution of exception handling program
• instructions to at least partially emulate said exception-triggering processing operation;
• and
• syndrome data storage means for storing syndrome data characterising said exception-triggering processing operation and including said data value;
• wherein
• said exception handling means performs said transfer with said given register means using said data value within said syndrome data;
• said syndrome data comprises replay state data having a first state and a second state;
• when said replay state data has said second state and upon attempted execution of said exception-triggering processing operation, said exception handling means sets said replay state data to said first state, and triggers execution of said exception handling program instructions;
• and
• when said replay state data has said first state and upon attempted execution of said exception-triggering processing operation, said exception handling means sets said replay state data to said second state, suppresses triggering of said exception handling program instructions and signals said exception-triggering processing operation as complete.

A method of processing data comprising:

• storing data within a plurality of registers;
• detecting attempted execution of an exception-triggering processing operation including a transfer of a data value with a given register of said plurality of registers;
• triggering execution of exception handling program instructions to at least partially emulate said exception-triggering processing operation;
• and
• storing syndrome data characterising said exception-triggering processing operation and including said data value;
• and
• performing said transfer with said given register using said data value within said syndrome data;
• said syndrome data comprises replay state data having a first state and a second state;
• when said replay state data has said second state and upon attempted execution of said exception-triggering processing operation, said detecting attempted execution sets said replay state data to said first state, and triggers execution of said exception handling program instructions;
• and
• when said replay state data has said first state and upon attempted execution of said exception-triggering processing operation, said detecting attempted execution sets said replay state data to said second state, suppresses triggering of said exception handling program instructions and signals said exception-triggering processing operation as complete.