Abstract: Systems and methods are disclosed for maintaining an instruction cache including extended cache lines and page attributes for main cache line portions of the extended cache lines and, at least for one or more predefined potential page-crossing instruction locations, additional page attributes for extra data portions of the corresponding extended cache lines. In addition, systems and methods are disclosed for processing page-crossing instructions fetched from an instruction cache having extended cache lines.

Abstract: An instruction in an instruction cache line having a first portion that is cacheable, a second portion that is from a page that is non-cacheable, and crosses a cache line is prevented from executing from the instruction cache. An attribute associated with the non-cacheable second portion is tracked separately from the attributes of the rest of the instructions in the cache line. If the page crossing instruction is reached for execution, the page crossing instruction and instructions following are flushed and a non-cacheable request is made to memory for at least the second portion. Once the second portion is received, the whole page crossing instruction is reconstructed from the first portion saved in the previous fetch group. The page crossing instruction or portion thereof is returned with the proper attribute for a non-cached fetched instruction and the reconstructed instruction can be executed without being cached.

Abstract: An instruction in an instruction cache line having a first portion that is cacheable, a second portion that is from a page that is non-cacheable, and crosses a cache line is prevented from executing from the instruction cache. An attribute associated with the non-cacheable second portion is tracked separately from the attributes of the rest of the instructions in the cache line. If the page crossing instruction is reached for execution, the page crossing instruction and instructions following are flushed and a non-cacheable request is made to memory for at least the second portion. Once the second portion is received, the whole page crossing instruction is reconstructed from the first portion saved in the previous fetch group. The page crossing instruction or portion thereof is returned with the proper attribute for a non-cached fetched instruction and the reconstructed instruction can be executed without being cached.

Abstract: Preventing execution of parity-error-induced unpredictable instructions, and related processor systems, methods, and computer-readable media are disclosed. In this regard, a method for processing instructions in a central processing unit (CPU) is provided. The method comprises decoding an instruction comprising a plurality of bits, and generating a parity error indicator indicating whether a parity error exists in the plurality of bits prior to execution of the instruction. If the parity error indicator indicates that the parity error exists in the plurality of bits, one or more of the plurality of bits are modified to indicate a no execution operation (NOP), without effecting a roll back of a program counter of the CPU and without re-decoding the instruction. In this manner, the possibility of the parity error causing an inadvertent execution of an unpredictable instruction is reduced.

Abstract: Systems and methods are disclosed for maintaining an instruction cache including extended cache lines and page attributes for main cache line portions of the extended cache lines and, at least for one or more predefined potential page-crossing instruction locations, additional page attributes for extra data portions of the corresponding extended cache lines. In addition, systems and methods are disclosed for processing page-crossing instructions fetched from an instruction cache having extended cache lines.

Abstract: A processor is operative to execute two or more instruction sets, each in a different instruction set operating mode. As each instruction is executed, debug circuit comparison the current instruction set operating mode to a target instruction set operating mode sent by a programmer, and outputs an alert or indication in they match. The alert or indication may additionally be dependent upon the instruction address following within a predetermined target address range. The alert or indication may comprise a breakpoint signal that halts execution and/or it is output as an external signal of the processor. The instruction address at which the processor detects a match in the instruction set operating modes may additionally be output. Additionally or alternatively, the alert or indication may comprise starting or stopping a trace operation, causing an exception, or any other known debugger function.

Abstract: A processor is operative to execute two or more instruction sets, each in a different instruction set operating mode. As each instruction is executed, debug circuit comparison the current instruction set operating mode to a target instruction set operating mode sent by a programmer, and outputs an alert or indication in they match. The alert or indication may additionally be dependent upon the instruction address following within a predetermined target address range. The alert or indication may comprise a breakpoint signal that halts execution and/or it is output as an external signal of the processor. The instruction address at which the processor detects a match in the instruction set operating modes may additionally be output. Additionally or alternatively, the alert or indication may comprise starting or stopping a trace operation, causing an exception, or any other known debugger function.