摘要:
The decoding of certain instructions cause an instruction unit of a production line data processing system to stall. Instructions still in the production line are executed, but no new instructions are sent into the production line until the instruction that caused the stall condition is executed. The execution of the instruction that caused the stall is completed by an execution unit taking over control of an address unit.
摘要:
A firmware controlled microprocessor plugged into a printed circuit board received firmware signals from a control store mounted on the printed circuit board. The number of pins required for transferring firmware signals is reduced by time sharing pins with firmware signal required for the full cycle of operation and firmware signal required only during the second half of the cycle of operation.
摘要:
A separate register file memory is included in at least two units of a pipelined processor which are located on separate integrated circuit chips. The register file memories of the units are interconnected so as to share certain input data register stages to enable updating to take place within a minimum of time. Each unit has a microprogrammed control unit which automatically provides update commands during the unit's cycles of operation. The signals from each microprogrammed control unit are applied to both register file memories enabling both memories to be updated during successive cycles of operation and thereby function collectively as one unit. This ensures that both units have access to the same most recently updated user visible information enabling both units to complete the execution of different instructions entering pipeline.
摘要:
The pipelined central processing system (CSS) units of a multiprocessor system are tightly coupled to connect in common to a system bus for sharing main memory and input/output controllers/devices. The CSS includes several circuit boards for the different VLSI circuit chip pipelined stages and associated control circuits in addition to the bus interface unit (BIU) circuits. Each board includes one or more unusual event (UEV) detector circuits for signaling when the behavior of a stage is abnormal. The UEV fault signals from each board are collected by the BIU board. When a UEV fault is detected, the BIU board circuits prevent any further communications with the system bus and broadcasts the UEV fault signal to the other boards causing the different pipelined stages to emulate the completion of the instructions within the pipeline thereby flushing it. It is thereafter placed in a nonpipelined mode. Control circuits execute a UEV handler microcode routine which reads the contents of syndrome registers included on each board containing the UEV indicator states in addition to error signals into register file working locations. The UEV signal is then cleared enabling the BIU to resume communications with the sytem bus.
摘要:
A pipelined processing unit which includes an instruction unit stage containing logic management apparatus for processing a set of complex instructions. The logic management apparatus includes state control circuits which produce a series or sequence of control states used in tracking the different types of instructions of the complex instruction set being processed. Different ones of the states are used for different types of instructions so as to enable the different pipeline stages to operate both independently and jointly to complete the execution of different instructions of the complex instruction set.
摘要:
A pipelined processing unit includes an instruction unit stage containing resource conflict apparatus for detecting and resolving conflicts in the use of register and indicator resources during the different phases of instruction execution. The instruction unit includes a plurality of resource registers corresponding in number to the number of instructions which can be processed concurrently by the processing unit. Decode circuits in response to each new instruction received by the instruction unit generate one or more sets of bit indication signals designating those resources required by the specific pipeline stage(s) executing the instruction for completing the execution of the instruction which are shared by those stages capable of completing the execution of instructions. Comparison circuits compare the set of bit indication signals for each new instruction that corresponds to resources needed by an earlier pipeline stage which in the preferred embodiment corresponds to a secondary execution unit, with the stored sets of bit indication signals for determining the presence of any resource conflict.
摘要:
In a data processing system using a virtual memory addressing scheme, certain software instructions call for the virtual address to be stored in a base register. The virtual address stored in the base register is incremented or decremented during the read out cycle of the previous operand to address the next operand. If the operand is not in physical memory, then the contents of the base register is restored to its original value. This invention minimizes the amount of logic required to back out of a software instruction after execution has begun and is faster than checking if all resources are present before any state change is made during the execution of a software instruction.
摘要:
A data processing system includes the functionality of a commercial instruction processor, a scientific instruction processor and a basic instruction processor integrated into a single semiconductor logic element.
摘要:
In a data processing system using a virtual memory adressing scheme, certain software instructions call for the virtual address to be stored in a base register. The virtual address stored in the base register is incremented or decremented during the read out cycle of the previous operand to address the next operand. If the operand is not in physical memory, then the contents of the base register is restored to its original value.
摘要:
A symmetric multiprocessing system with a unified environment and distributed system functions provides unified address space for all functional units in the system while distributing the execution of various system functions over the functional units of the system whereby each functional unit assumes responsibility for its own aspects of these operations. In addition, the system provides improved system bus operation for transfer of data from memory.