Abstract: Dynamic redundancy buffers for use with a device are disclosed. The dynamic redundancy buffers allow a memory array of the device to be operated with high write error rate (WER). A first level redundancy buffer (e1 buffer) is couple to the memory array. The e1 buffer may store data words that have failed verification or have not been verified. The e1 buffer may transfer data words to another dynamic redundancy buffer (e2 buffer). The e1 buffer may transfer data words that have failed to write to a memory array after a predetermined number of re-write attempts. The e1 buffer may also transfer data words upon power down.

Abstract: Dynamic redundancy buffers for use with a device are disclosed. The dynamic redundancy buffers allow a memory array of the device to be operated with high write error rate (WER). A first level redundancy buffer (e1 buffer) is couple to the memory array. The e1 buffer may store data words that have failed verification or have not been verified. The e1 buffer may transfer data words to another dynamic redundancy buffer (e2 buffer). The e1 buffer may transfer data words that have failed to write to a memory array after a predetermined number of re-write attempts. The e1 buffer may also transfer data words upon power down.

Abstract: Dynamic redundancy registers for use with a device are disclosed. The dynamic redundancy registers allow a memory bank of the device to be operated with high write error rate (WER). A first level redundancy register (e1 register) is couple to the memory bank. The e1 register may store data words that have failed verification or have not been verified. The e1 register may transfer data words to another dynamic redundancy register (e2 register). The e1 register may transfer data words that have failed to write to a memory bank after a predetermined number of re-write attempts. The e1 register may also transfer data words upon power down.

Abstract: Dynamic redundancy buffers for use with a device are disclosed. The dynamic redundancy buffers allow a memory array of the device to be operated with high write error rate (WER). A first level redundancy buffer (e1 buffer) is couple to the memory array. The e1 buffer may store data words that have failed verification or have not been verified. The e1 buffer may transfer data words to another dynamic redundancy buffer (e2 buffer). The e1 buffer may transfer data words that have failed to write to a memory array after a predetermined number of re-write attempts. The e1 buffer may also transfer data words upon power down.

Abstract: Dynamic redundancy buffers for use with a device are disclosed. The dynamic redundancy buffers allow a memory array of the device to be operated with high write error rate (WER). A first level redundancy buffer (e1 buffer) is couple to the memory array. The e1 buffer may store data words that have failed verification or have not been verified. The e1 buffer may transfer data words to another dynamic redundancy buffer (e2 buffer). The e1 buffer may transfer data words that have failed to write to a memory array after a predetermined number of re-write attempts. The e1 buffer may also transfer data words upon power down.

Abstract: Dynamic redundancy registers for use with a device are disclosed. The dynamic redundancy registers allow a memory bank of the device to be operated with high write error rate (WER). A first level redundancy register (e1 register) is couple to the memory bank. The e1 register may store data words that have failed verification or have not been verified. The e1 register may transfer data words to another dynamic redundancy register (e2 register). The e1 register may transfer data words that have failed to write to a memory bank after a predetermined number of re-write attempts. The e1 register may also transfer data words upon power down.

Abstract: A cache-based computer architecture is disclosed in which the address generating unit and the tag comparator are packaged together and separately from the cache RAMs. If the architecture supports virtual memory, an address translation unit may be included on the same chip as, and logically between, the address generating unit and the tag comparator logic. Further, interleaved access to more than one cache may be accomplished on the external address, data and the tag busses.

Abstract: A cache-based computer architecture has the address generating unit and the tag comparator packaged together and separately from the cache RAMS. If the architecture supports virtual memory, an address translation unit may be included on the same chip as, and logically between, the address generating unit and the tag comparator logic. Further, interleaved access to more than one cache may be accomplished on the external address, data and tag busses.

Abstract: A digital system that includes a plurality of integrated circuits disposed on a circuit board, each integrated circuit comprising a plurality of scan chains, each scan chain scanning data from a scan input to a scan output in response to a scan clock; each scan input is coupled to a first pad of the integrated circuit, and the scan outputs are multiplexed to a second pad of the integrated circuit; the second pads of the integrated circuits are multiplexed to a port of the circuit board. A controller selects one of the integrated circuits for scanning, the controller selecting the second pad of the selected integrated circuit for coupling to the port of the circuit board; and the controller also selects one of the plurality of scan chains in the selected integrated circuit for scanning, the controller coupling the scan clock to the selected scan chain and selecting the scan output of the selected scan chain for coupling to the second pad of the selected integrated circuit.

Abstract: Apparatus is disclosed for buffering writes from a CPU to main memory, in which sequential write requests to the same address are gathered and combined into a single write request. The embodiment described does not permit gathering with the write request in the buffer which is next scheduled for action by the main memory bus controller, nor does it permit gathering with other than the immediately preceding write request. The invention is implemented using a plurality of buffer ranks, each comprising a data rank, an address rank, and a valid rank for indicating which bits or bytes of the data rank contain data to be written to memory.

Abstract: A method and data processing system for validating prefetch instruction. The system includes an instruction unit, an n-stage pipeline which provides data segments representing instruction words from a memory to the instruction unit. The system further includes a circuit for prefetching instruction words to be executed subsequently to a presently executing instruction and a circuit for verifying the validity of the prefetched instruction word prior to execution thereof by the execution unit, and a circuit for causing the instruction unit to a fault condition only when the execution of an invalid instruction is begun.

Abstract: A method and data processing system for validating prefetch instruction. The system includes an instruction unit, an n-stage pipeline which provides data segments representing instruction words from a memory to the instruction unit. The system further includes a circuit for prefetching instruction words to be executed subsequently to a presently executing instruction and a circuit for verifying the validity of the prefetched instruction word prior to execution thereof by the execution unit, and a circuit for causing the instruction unit to a fault condition only when the execution of an invalid instruction is begun.

Abstract: In a data processor adapted to perform operations upon operands of a given size, a bus controller is provided to communicate the operands with a storage device having a data port which may be a submultiple of the operand size. In response to a signal from the bus controller requesting the transfer of an operand of a particular size, the storage device provides a size signal indicating the size of the data port available to accommodate the requested transfer. Depending upon the size of the operand to be transferred and the size of the data port of the storage device, the bus controller may break the operand transfer cycle into several bus cycles in order to completely transfer the operand. In the process, the bus controller compensates for any address misalignment between the operand and the data port.

Abstract: A data processor capable of automatically storing in an external memory all essential information relating to the internal state thereof upon the detection of an access fault during instruction execution. Upon correction of the cause of the fault, the data processor automatically retrieves the stored state information and restores the state thereof in accordance with the retrieved state information. The data processor then resumes execution of the instruction. The faulted access may be selectively rerun upon the resumption of instruction execution. Means are provided to verify that the retrieved state information is valid.

Abstract: An integrated circuit data processor receives interrupt level signals from external circuitry which represent a priority level associated with the external circuitry. These signals are compared with signals representing the current operating level of the processor, and an interrupt pending output is generated if (1) the priority level is higher than the operating level; or (2) a maximum priority level is received. Upon the occurrence of the interrupt pending output, the current instruction program is interrupted, and an instruction program associated with the external circuitry is executed. The processor transmits a signal back to the external circuitry indicating that the interrupt request has been granted and receives a vector number from the external circuitry. A first acknowledgment signal from the external circuitry causes the vector number to be latched in the processor. A second acknowledgment signal from the external circuitry causes a vector to be internally generated.

Abstract: An integrated circuit microprocessor includes storage means coupled to a control unit for receiving from the control unit information regarding how the next bus cycle is to be run. Upon receipt of a bus error signal from a peripheral device, the storage means is reset. If, however, a halt signal accompanies the bus error signal, the storage means is not reset and the bus cycle is rerun when the halt signal terminates.