摘要:
A programmable pipeline depth controller is provided to control the number of instructions that begins execution within an instruction pipeline of an instruction processor within a predetermined period of time. The pipeline depth controller of the present invention includes a logic sequencer responsive to a programmable count value. Upon being enabled, the logic sequencer generates a pipeline control signal to selectively delay the entry of some instructions into the instruction pipeline so that the number of instructions that begins execution within the instruction pipeline during the predetermined period of time following the enabling of the logic sequencer is equal to the count value.
摘要:
A system and method are provided for detecting and recovering from errors in an Instruction Cache RAM and/or Operand Cache RAM of an electronic data processing system. In some cases, errors in the Instruction Cache RAM and/or Operand Cache RAM are detected and recovered from without any required interaction of an operating system of the data processing system. Thus, and in many cases, errors in the Instruction Cache RAM and/or Operand Cache RAM can be handled seamlessly and efficiently, without requiring a specialized operating system routine, or in some cases, a maintenance technician, to help diagnose and/or fix the error.
摘要:
Instruction processor and method supporting dual-mode execution of computer instructions. In various embodiments, certain instructions are executable in one of two modes. The first mode is compatible with the native instruction set and data words, and the second mode is an adaptation suitable for platform independent instructions. A control word RAM is addressed by the operation code of an instruction, and each word in the control word RAM includes an address into a microcode RAM. The address into the microcode RAM is manipulated in accordance with the various embodiments to reference either a first set of microcode for native instructions and data words, or a second set of microcode for execution in a platform-independent mode.
摘要:
A method and apparatus for efficiently requesting the instruction processor to store its state information directly to main memory storage is provided by a single instruction command. An advantage is a performance improvement over the prior art since the time-consuming tasks of transferring Local Area Network (LAN) messages and scanning the instruction processor are eliminated. An additional advantage is a savings in computer time since the System Control Facility (SCF) and Network Interface Module (NIM) are not required to store the instruction processor state information. Yet another advantage is large amounts of additional hardware are not required. The same control logic used to generate the o-cache jump-history entry is used to generate the store software instrumentation package instruction which requests the instruction processor to store its state information directly to main memory storage.
摘要:
A digital instruction processor control system for an instruction processor having a multiple stage instruction execution pipeline capable of executing binary instructions in fixed predetermined stages. The control system includes a hardware controller to generate control signals for execution of all pipeline stages of standard instructions and for the first stage of extended cycle instructions and provides a main microcode controller to provide programmed control signals for controlling all subsequent stages of execution of extended cycle instructions. The control system also utilizes a separate sequence microcode controller for execution of certain instructions of a predetermined type including decimal instruction execution, during which time the main microcode controller is under control of the separate sequence controller.
摘要:
An apparatus for and method of controlling branching conditions within a pipelined instruction processor. For jump instructions, a memory is used to store the target address of branches actually taken as a function of the absolute address of the jump instruction. The next time the same jump instruction is executed, the branch is assumed and the target address is supplied to the instruction pipeline for prefetching of the target instruction. If the conditional branch instruction is a skip instruction, interdependency of the Nth and N+1st instructions are determined by comparison of the index register fields. If no dependency is found, fully pipelined operation is continued. If a dependency is found, the system is depiped for one clock cycle to prevent the N+1st instruction from using an index register which has not been updated as anticipated by the software developer.