Abstract:
The present invention relates to a family of parity-checked shift register counters having a counting period not determined by a power of 2 wherein the power is determined by the number of shift register stages. It will be apparent that the range of the counter is effected by the number of stages but not necessarily the actual count. The family of counters is further characterized in that either odd or even parity may be designed into the output pattern of said counter, which parity will be automatically maintained for all binary-bit patterns to produce. The family of counters is further characterized in that they require only N+6 logic circuits wherein there are N shift register stages, four 2input exclusive ORs and 2 N input AND circuits. The counters are also characterized in that they are self testing. That is, all components are tested for faults in normal operations.
Abstract:
The error tolerant arithmetic logical unit is divided into vertical bit-planes which are relatively independent, being coupled mainly for the purposes of shifts and carry propagation. The system tolerates failures and still functions correctly by reconfiguring the unit through the control of interplane connections. By inserting a spare bit-plane into the system and switching between bit-planes to bypass a failed plane, the effect of the failed plane or of a failure in a position of control logic can be eliminated.
Abstract:
A series of self-checking error checking circuits are disclosed for checking conventional parity coded data lines. The data signal set includes any logical combination of binary ''''1''s'''' and ''''0''s'''' and at least one parity bit. The circuit comprises at least 2 exclusive OR tree circuits wherein each tree obtains its inputs from different input lines whereby complementing outputs are produced by the two tree circuits for any correct signal set and wherein the checker is error free. Any error in the data will cause the two outputs to be the same. Malfunctions or failures in the checking circuit are checked by certain legitimate code signals which similarly cause an error representation in the output of the checker.
Abstract:
A computer system of the standby redundancy type including three active logic modules and at least one spare module, characterized by the provision of triple modular redundancy means for correcting and locating the failure of a first one of said active logic modules, in combination with sparing means for reconfiguring the system to by-pass the faulty module and to substitute the spare module therefor. The invention is further characterized by the provision of means for reintroducing the first module into the system upon the detection of failure of another active module.
Abstract:
A SERIES OF SELF-CHECKING ERROR CHECKING CIRCUITS ARE DISCLOSED FOR CHECKING TWO-RAIL LOGIC CODED DATA LINES. THE DATA LINES ARE ARRANGED AS N PAIRS OF TWO-RAIL GROUPS. ONE FORM OF THE CHECKER COMPRISES N-1 BASIC TWO OUTPUT BLOCKS CONNECTED IN A GENERAL TREE CONFIGURATION ACROSS THE TWO-RAIL DATA LINES. EACH OF SAID BASIC BLOCKS HAS TWO NORMALLY COMPLEMENTARY OUTPUT LINES AND THE LAST STAGE OF THE CHECKER IS A SINGLA BASIC BLOCK. IF AN INVAID CODE IS RECEIVED, THE TWO OUTPUTS WILL BE IDENTICAL. MALFUNCTIONS OR FAILURES IN THE CHECKING CIRCUIT ARE CHECKED BY CERTAIN LEGITIMATE CODE SIGNALS WHICH SIMILARLY CAUSE AN ERROR REPRESENTATION IN THE OUTPUT OF THE CHECKER WHEREBY BOTH OUTPUTS WILL BE IDENTICAL.
Abstract:
Mapping control means for achieving error toleration in computer addressing circuitry including switching means for connecting an address register with the effective address register of a basic operating module. The switching means are operable by a blocking register and at least one status register to control the mapping connections in a given manner. The invention is characterized by the provision of an address blocking register and a mask register that process a sequence of failed addresses and insert corresponding control instructions in the blocking and status registers so that the switching means dynamically excludes access to the memory area affected by the faulty address circuitry.
Abstract:
A self-testing error-checking system for inclusion in a computer comprising a plurality of self-testing check circuits, each said circuit having a two-rail complementary output whenever both the circuits being tested and the checking circuit is operating properly and an identical output on each of the two output lines whenever a fault is detected. The improvement which comprises reduction checking means connected to all said two-rail outputs from said checking circuits, and means connected to the output of said reduction checker means for at least indicating that a failure has occurred. The output of said reduction checker itself is two rail and complementary when all inputs are correct and the checker itself is operating properly. The output of the present checking system may be connected to a computer interrupt circuit or to a visual logout means. Alternatively, the system output may be utilized to effect automatic self-repair.
Abstract:
A SERIES OF SELF-CHECKING ERROR CHECKING CIRCUITS ARE DISCLOSED FOR CHECKING K-OUT-OF-N CODED DATA LINES. THE N LINES ARE BROKEN INTO TWO, PREFERABLY EQUAL, GROUPS. A LOGIC EQUATION IS DERIVED FOR EACH GROUP OF LINES WHEREBY, WITH ANY K-OUT-OF-N CODED DATA SIGNALS APPLIED TO THE INPUT, AT LEAST TWO COMPLEMENTARY OUTPUT SIGNALS ARE PRODUCED. ANY ERROR APPEARING IN THE RECEIVED CODE WILL BE INDICATED AS SUCH BY NON-COMPLEMENTARY OUTPUTS FROM
THE CHECKER IN THE OUTPUT OF THE CHECKER. MALFUNCTIONS OR FAILURES IN THE CHECKING CIRCUIT ARE CHECKED BY CERTAIN LEGITIMATE CODE SIGNALS WHICH SIMILARLY CAUSE AN ERROR REPRESENTATION IN NON-COMPLEMENTARY OUTPUTS AT THE OUTPUT OF THE CHECKER.