摘要:
A cache memory including an even data store for storing data words associated with even address numbers and an odd data store for storing data words associated with odd address numbers, a local bus for transferring a low order data word and a high order data word simultaneously from the cache memory to a system element requesting the transfer of a pair of data words through the supplying of a single address number request, and a data steering multiplexer for supplying the data word associated with the memory request number, as outputted from either the odd or even cache data store to the low order data word transfer portion of the local bus and the other of the pair of data words outputted from the odd or even data store to the high order data word transfer portion of the local bus.
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 first delay line coupled to an inverter by using a multitapped second delay line to delay the rectangular wave train by selectable predetermined 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 the rectangular wave train clock cycle period plus the period of the second selected predetermined delay. By serially connecting a multitapped third delay line in series with the second delay line and by providing a first switch to select one of the outputs from said third delay line, the clock cycle period of the clock system may be adjusted. Use of a multitapped delay line for the first delay line and the addition of a second switch for selection among the various delayed signals of the first delay line, enable selective adjustment of clock pulse width.
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:
Interrupt service is enabled for either a real-time clock or watchdog timer time out condition. A mode register is provided to effectively enable or disable the interrupt apparatus and if enabled is coupled to enable a service register in response to repetitively occurring clock pulses. Each time the service register is enabled, a counter is changed in value until a predetermined value is indicated at which time interrupt service is enabled at an interrupt level specified by the operator. Further, facilities are provided for presetting the value of the counter in an expeditious manner.
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.