摘要:
In a data processing system, interrupt service is provided for any one of a plurality of interrupt sources which presents an interrupt signal which has a higher interrupt level than that of the currently active source. Interrupt flags are provided for each potential interrupt source, which flags are activated in response to the receipt of an interrupt signal from the interrupt source associated therewith. A scan for the highest interrupt level is made and interrupt service is provided for the interrupt source associated therewith.
摘要:
A data processing system having a plurality of interrupt sources coupled to provide interrupt handling of a process currently executing at a specified interrupt level. A level change signal which may be generated by the process itself may change the specified level of such process to another level which may make such process less interruptable to other interrupt sources. The level change provided takes place without interrupting the execution of such process.
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 clock system for providing rectangular wave forms or wave trains, with each wave train having a selectable predetermined clock cycle period. A rectangular wave train is generated by a generator comprising a delay line coupled to an INVERTER. By using a second delay line to delay the rectangular wave by a selectable predetermined delay period, a control signal is formed which when fed into the generator produces a second rectangular wave train with a clock cycle period equal to that of the rectangular wave clock cycle period plus the period of the second predetermined delay. The addition of a synchronization circuit permits the clock cycle period to be dynamically selected during a clock cycle. This provides a rectangular train with the period of each clock cycle being any of the predetermined clock cycle periods independent of the clock cycle period of preceding or succeeding clock cycles.
摘要:
A final effective address of an operand is generated in a microprogrammed data processing system by use of a base address register which may include an unindexed address, an index register which may include an index address value, an instruction register which may include an instruction word, which instruction word provides control over the addressing of a control store dependent upon the state of a selected one of a plurality of test conditions. The addressed control store word provides signals for controlling the operation of the system, including the branching between such major operations as instruction fetching, addressing, reading, writing, and execution as well as branching between minor operations which are included in the major operations.