Patent ID: 6243836
Filing Date: 2001-06-05
Classification: G06F

Abstract:
A method for providing circular buffering of on-chip program tracing for a processing device comprising the steps of:reading a bit stream output from said processing device, said bit stream comprising a plurality of types instructions executed by said processing device;parsing each of said plurality of trace codes into an address component and a code component;a generating a link component between a store address component of a trace code just read with a previously read trace code, said link component being a value representing an address of a location in a memory and further comprising;setting said link component to a first value;replacing said first value of said link component of a previous transformed code with a value representing an address location of said memory where said code component, address component, and link component of a just read trace code are store; andstoring said code component, said address component, and said link component generated for said trace code just read in a buffer;storing said code component of a said trace code in said memory if said trace code is of a first type;storing said code component, said address component and said link component as a transformed code in said memory if said trace code is of a second type, wherein said second type code is a discontinuity type instruction;maintaining said memory as a circular buffer using said link component to modify a previously stored transformed code with said link component; andcomparing a value representing a staring address of said memory with a value representing a current address, said current address being associated with an area in said memory for storing a next read transformed code.