摘要:
A logic control system is disclosed for accommodating the flow of both procedural information and CPU (central processing unit) instructions from a central memory system to a CPU without compromising memory bandwidths or CPU execution speeds because of transfer delays or timing variances. Instruction modifications and plural task assignments are accommodated during instruction execution.
摘要:
In a data processing system, a central processor unit requests procedural data words or non-procedural data words stored in the system memory. A control store device executes firmware instructions including a local bus field for controlling the transfer of the requested procedural data words and non-procedural data words to the central processor unit. The requested procedural data words and non-procedural data words are transferred to the central processing unit by an interfacing device including a data bus latch for receiving the procedural data words and non-procedural data words transferred from the memory, a prefetch buffer for storing up to four words, a first set of OR gate circuits for selectively transferring the procedural data words stored in the prefetch buffer to a procedural data multiplexer for assembling either a procedural data word or a procedure address, and a second set of OR gate circuits for selectively transferring either a procedural data word or non-procedural data word to the source bus or a procedural data address or non-procedural data address to the source bus for transfer to the central processor unit.
摘要:
A data processing system includes a memory subsystem for storing operands and instructions and a central processing unit (CPU) for manipulating the operands by executing the instructions. The CPU includes a control store for generating signals for controlling the CPU operation. Shifters made up of multiplexers shift operands between an outer bus and a write bus in response to control store signals. The multiplexers shift the operands left or right 1, 2 or 4-bit positions including open shifts and circular shifts and also perform byte position shifting and twinning.
摘要:
A logic control system comprised of a cache memory system and a transfer control logic unit is disclosed for accommodating the flow of both procedural information and CPU (central processing unit) instructions from a central memory system on a common communication bus to a CPU. The CPU and the transfer control logic unit communicate by way of the cache memory system with the common communication bus. In response to a CPU request to the central memory system, procedural information and instructions are requested by the transfer control logic unit from the cache memory system and presented to the CPU in such a manner as to avoid interruptions in CPU activity caused by information transfer delays.
摘要:
A first bank or a second bank of storage locations of a control store of a data processing system is enabled in response to one of a plurality of test signals received as parallel inputs by two multiplexer devices. Only one of the multiplexers is enabled at a given time in response to the polarity of one of the test signals selected from the inputs of the multiplexer devices.
摘要:
A logic control system is disclosed for accommodating the flow of both procedural information and CPU (central processing unit) instructions from a central memory system to a CPU without compromising memory bandwidths or CPU execution speeds because of transfer delays or timing variances. Instruction modifications and plural task assignments are accommodated during instruction execution.
摘要:
This disclosure relates to a control system for transferring binary words from a memory system. One thirty two bit double word may be loaded into a selected two of four sixteen bit registers. As a first of the two selected registers is read, another thirty two bit word may be loaded into the unselected registers. Alternatively, sixteen bit single words may be loaded into and read from the registers. When a word has procedural information, it is read from the registers onto a CPU control bus via a multiplexer. When a word is an encoded computer instruction to the CPU, it is read from the registers into a logic unit via a multiplexer. A decoded instruction from the logic unit is read onto a CPU control bus.
摘要:
A data processing system includes a first memory for storing microinstructions in a first plurality of storage locations and second memory for storing microinstructions in a second plurality of storage locations. A central processor executing a series of addressed microinstructions to control the functions performed by this system generates the address of the next microinstruction to be executed in series as well as a next address selection signal. Addressing circuitry concurrently applies the next address generated by the processor to address inputs of each of the first memory and the second memory. After a predetermined delay, either the first memory or the second memory is selected to output an address microinstruction responsive to the value of the next address selection signal.
摘要:
A technique and apparatus for storing data and addressing stored data in a memory from which multiple words of data are to be retrieved in parallel is disclosed. The memory is addressed by providing the address of the first of N consecutive words to be retrieved in parallel. The data is stored in memory in physical data words which contain N logical data words such that the addressing of one physical data word will result in N logical data words being read in parallel from the memory. Each physical data word contains the contents of the logical data word having the same address as that of the physical data word in its leftmost position followed in the next right position by the contents of the logical data word having the next higher address, and so on until the rightmost position of the physical data word contains the contents of the logical data word with an address equal to the physical data word address plus N-1. This results in the contents of each logical data word being stored N times in the memory, but eliminates the need for data alignment as the N logical data words are read in parallel from the memory.
摘要:
A control store included in a data processing system for storing microinstructions in a plurality of microinstructions storage locations is organized in two parts, an upper bank and a lower bank. The lower bank is directly addressed by a portion of the currently addressed control store word, whereas the upper bank is addressed by use of a multiplexer, with inputs thereto coupled from various logic elements. Apparatus is included to determine which part of the control store will be selected and to allow such determination at a time substantially after the addresses for the first and second parts have been received by the control store. In addition, the elements included in the upper bank are selected to have address propagation time sufficiently faster than the address propagation time of the lower bank to compensate for the additional logic propagation delay introduced by the multiplexer so that the contents of the addressed locations of the upper and lower banks are available for use by the system at substantially the same time.