摘要:
A redundancy circuit and method allows replacement of failed memory cells in a semiconductor memory array. Redundancy true and redundancy not comparator circuits are provided in dynamic logic to selectively enable and disable respective redundant row predecode and normal row predecode circuits. In one embodiment, redundancy circuits are row redundancy circuits. As compared with single static row redundancy comparator circuits which are limited by setup time constraints and which degrade access time irrespective of redundant row utilization, a dual dynamic comparator design reduces access time penalties when redundancy is enabled and eliminates access time penalties when redundancy is not required in a particular semiconductor memory array.
摘要:
Multi-port RAM having a RAM core and signal transfer circuit transforming a predetermined signal between the RAM core and a random logic portion. The signal transfer circuit includes a scan path circuit. The scan path circuit for an address signal (ASCAN0), a scan path circuit for a data input signal (DSCAN0) and a selector circuit (ASEL) are provided on the write side, and no scan path circuit is provided on the read side. A read address is supplied through selector circuits (FSEL 2 and RSEL2) termed read address supply device provided on the read side. Thus, reduction of the test circuit allows area reduction of a chip and cost cutting in a semiconductor integrated circuit.
摘要:
A data processing system has at least one processing module containing one or more blocks of memory, having control registers which are accessible via a diagnostic interface, and a clock module which distributes system clocks to the processing module(s), the operation of which is controllable using a similar diagnostic interface. One of the possible actions in the clock module is the generation of a single-shot clock pulse. A diagnostic control unit is connected to the separate diagnostic interfaces of the processing module(s) and the clock module, and is capable of simultaneously controlling the two diagnostic interfaces in such a way that a single-shot clock pulse can be synchronized with the diagnostic access to a processing module to effect the loading or dumping of a block of memory line by line.
摘要:
A serial memory interface includes a register having a plurality of flip-flops forming a scan chain and coupled to both the input and output terminals of memory cells. An interlaced scan is established by interconnecting scan chains between multiple memory blocks. The interface structure provides a means for efficiently performing a built-in self test of an embedded memory while requiring minimal overhead in hardware structure.
摘要:
A serial scan path communication architecture includes a plurality of circuits (30), some of which may include a memory (36). A memory access controller (38) is included on circuits with a memory (36) such that serial data may be written to and written from the memories without having to repetitively cycle through multiple shift operations.
摘要:
Computer system element has a VLSI array with redundant areas and an ABIST (Array Built-In Self Test system). The ABIST controller allows self test functions (e.g. test patterns, read/write access, and test sequences) to be used with dual logical views to reduce test time. The ABIST generates pseudo-random address patterns for improved test coverage. A jump-to-third pointer control command enables branching to perform looping after a background has been filled. A data register is divided into multiple sections to enable a Walking/Marching pattern to be executed individually and concurrently in the dual views to further reduce test times.
摘要:
An integrated circuit with programmable transistors is programmed via a state machine on the integrated circuit. For example, the integrated circuit may be a programmable logic device, and the state machine may be a JTAG state machine. Each integrated circuit may have on it a register containing data indicating how long a particular programming operation should continue in order to be successful for that circuit. External programming control apparatus first reads that data and then at least partly bases the timing of programming instructions applied to the integrated circuit on that data. The integrated circuit may have an on-board programming voltage generating circuit which is turned on only by appropriate instructions from the external programming control apparatus. The external programming control apparatus controls the sequence and timing of all programming operations via the state machine port of the integrated circuit.
摘要:
A semiconductor memory device includes a plurality of memory blocks, a write circuit for writing data into the memory blocks, a read circuit for reading data from the memory blocks, a plurality of serial registers, each of which is connected to the corresponding memory block to output serially a plurality of data read from the memory block, a plurality of switches, each of which is arranged between two adjacent ones of the serial registers to connect the serial registers in series, and a coincidence detection circuit for detecting a coincidence of data outputted from a final serial register arranged at a final end of the serial registers connected by the switches with data outputted from a serial register arranged immediately before the final serial register.
摘要:
To carry out a transparent test of integrated circuits, all of the state registers and input/output registers that determine the applications' execution context are included into circular scan paths having the output of the last stage connected to the input of the first stage. Before the test, the contents of the registers are shifted via the scan path into a RAM. After the test, the saved contents of the registers are reloaded from the RAM to the registers via the scan path.
摘要:
A method and apparatus is provided for testing self timed memory arrays which does not affect the state of cells within the arrays not being tested. Each memory array has a plurality of control, address and data registers which are coupled to the respective control, address and data lines into the memory array. A timing generator circuit receives an external clock pulse and provides the self-timed clock pulses to the memory array. During the shift mode, the control, address and data registers are chained together such that data for testing can be scanned serially into the registers. In order to prevent unplanned array modification operations from occurring during the shift mode because a bit shifted into the write-enable or clear register at the time a clock pulse derived from the timing circuitry is generated, a logic means is provided to disable all clock pulses during the shift mode. A separate shift clock pulse is provided during shift mode to shift the test information into the control, address and data registers. Once the information is shifted in, a separate test clock pulse is issued to cause the operation indicated by the data in the address, control and data registers to be performed. Thus, the operation identified by the control address and data registers is performed without affecting the state of the control registers of adjacent memory arrays and without affecting the state of other memory cells and components on the chip while maintaining the same temporal state of the chip.