摘要:
Multi-phase subroutine control apparatus for use in a data processing system which provides for the concurrent execution of a plurality of tasks in a multiprogramming and multiprocessing environment. Subroutine control operations are staged so as to share common hardware in a manner which in effect provides a plurality of phased concurrently operating subroutine control circuits wherein each circuit provides control for a different one of a plurality of concurrently executing tasks. The common subroutine hardware includes a multi-level stack for each task and a fast access return address register which permits a return address to be rapidly made available when required during execution of a task.
摘要:
Subroutine control apparatus for providing shared subroutine control for a plurality of executing tasks. Multiple levels of subroutine entry are provided for each task by employing a plurality of selectably accessible stacks, one for each task, along with corresponding pointer registers. These provide storage for a plurality of return addresses as required for each task during task performance. In addition, an updatable significantly faster access register is provided for each task for storing its most recent return address so as to permit return addresses to be rapidly made available when an executing task reaches the end of a subroutine.
摘要:
@ A microprocessor-controlled interface for permitting any digital host computer to receive serial digital data from any instrument wherein (a) the time at which digital data from the instrument is to enter the host computer and (b) the logical structure of the digital data entering the host computer are controlled by instructions from the host computer to the microprocessor and wherein (a) physical formatting incompatibilities between the host computer and the instrument and (b) the communicating of prohibited characters from the instrument to the host computer and vice versa are avoided. The timing control and logical structure of the digital data are effected by directing data from the instrument into a scratchpad memory, which is divided into records pursuant to instructions from the host computer, the contents of the scratchpad memory being sent to the host computer upon a corresponding instruction therefrom. A terminal for communicating with the host computer and the instrument may be included. Physical formatting discrepancies are avoided by translating inputs to the interface into a common physical format and translating outputs from the interface into the physical format of the instrument, host computer, or terminal which is receiving such outputs. Because about 90% of all current digital devices are formatted in a manner translatable by a selected one of three translator elements, a small number of interfaces formatted for a specific host computer (and terminal) can be used with a vast number of different instruments by accounting only for the instrument physical format and associated prohibited characters. Instructions, selected from a set of distinct instructions, which are sent from the computer to the microprocessor determine (a) whether a terminal-host computer, instrument-host computer, or terminal-instrument communication channel is to be open, (b) whether all channels are to be closed, and (c) when other communication transfer operations are to be executed. Terminal-host computer communications can occur at least substantially simultaneously with the directing of digital data from the instrument to the scratchpad memory.
摘要:
In a microcomputer a random access memory (12) and a central processor unit (11) are mounted on a single chip and are connected therebetween by a bus line (BUS). Bit lines (BL, BL) of the memory are extended to internal registers of the central processor unit, and a connecting portion (10) which can read and write is provided therebetween. When data bits from an internal register are saved, one word line of the memory is selected and all bits of the data are transferred simultaneously to a memory cell group connected to the word line.