Logic kỹ thuật số thử nghiệm và mô phỏng P9
Logic kỹ thuật số thử nghiệm và mô phỏng P9
... been developed over the years to test digital logic circuits. Some of these methods can trace their origins back to the very beginnings of the digital logic era. Unfortunately, they have proven ... IC. 2 These flip-flops can help to isolate an IC from other logic on the PCB, making it possible to test the IC independent of that other logic. This makes it possible to diagnose and repair P...
Ngày tải lên: 07/11/2013, 20:15
Logic kỹ thuật số thử nghiệm và mô phỏng P2
... of logic, is the set of elements encoun- tered during a backtrace from an internal circuit node, called the apex, to input state points. Definition 2.3 A predecessor of a logic element is a logic ... behavior. 2.4 THE LOGIC SYMBOLS Test problems, as well as other circuit issues, are often described most effectively by means of schematic diagrams. Figure 2.1 introduces the logic symbol...
Ngày tải lên: 17/10/2013, 22:15
Logic kỹ thuật số thử nghiệm và mô phỏng P3
... follows, the positive logic convention will be used. Any voltage between ground (Gnd) and +0.8 V represents a logic 0. A voltage between +2.4 V and +5.0 V (Vcc) represents a logic 1. A voltage between ... arbitrarily selected and required to generate a logic 1, then the upper AND gate must generate a logic 1, requiring that inputs X 1 and X 2 must both be at logic 1. As before, a...
Ngày tải lên: 20/10/2013, 17:15
Logic kỹ thuật số thử nghiệm và mô phỏng P4
... , is an AND gate, and a logic 1 on its output only occurs if all its inputs have logic 1 values. This is called implication ; a 1 on the output of an AND gate implies logic 1 on all its inputs. ... greater difficulties because a logic assignment at its upper input must be justified through other logic, and a test at its output must be propagated through additional logic. An arbitrary...
Ngày tải lên: 20/10/2013, 17:15
Logic kỹ thuật số thử nghiệm và mô phỏng P5
... only through logic operators, but also through an entirely new dimension—time. The time dimension may be discrete, as in synchronous logic, or it may be continuous, as in asynchronous logic. The ... CAUSED BY SEQUENTIAL LOGIC Two factors complicate the task of creating tests for sequential logic: memory and circuit delay. In sequential circuits the signals must not only be logically co...
Ngày tải lên: 24/10/2013, 15:15
Logic kỹ thuật số thử nghiệm và mô phỏng P6
... 2 PW 2 296 AUTOMATIC TEST EQUIPMENT Pin data PD 1 and PD 2 are identical; a logic 1 in pin memory is followed by a logic 0, another 1, and then a 0. However, because the timing generators are ... if all of them fail in an identical fashion, then the logical assumption is that there is a design error that occurred during either the logic design process or the physical design process. ......
Ngày tải lên: 24/10/2013, 15:15
Logic kỹ thuật số thử nghiệm và mô phỏng P7
... addition, state machines, control paths, and other logic that are synthesized via synthesis programs may receive addi- tional scrutiny from the logic designer if subsequent simulation or timing ... cuit in Figure 2.8. The signal 1’b1 connected to the preset in the dff denotes a logic 1. Similarly, 1’b0 denotes a logic 0. The next element in ckt7p3 is called bufif1 . The bufif1 is a tri-...
Ngày tải lên: 28/10/2013, 22:15
Logic kỹ thuật số thử nghiệm và mô phỏng P8
... lesser num- ber contained the more complex control logic and handshaking protocols. Test programs for control logic would be created by requiring a logic designer or test engineer to write vectors ... the output of the AND gate fans out to other logic, that one gate affects observability of logic up to that point and it affects controllability of logic following that node. (a) (b)...
Ngày tải lên: 28/10/2013, 22:15
Logic kỹ thuật số thử nghiệm và mô phỏng P10
... array faults, and read/write logic faults. From there we use the fact, demonstrated by Nair, Thatte, and Abraham, 7 that faults in memory addressing and read/write logic, which includes sense ... coupling fault between cells. If no cell is addressed, then, depending on the logic, the response from the read logic may appear as a stuck-at-1 or a stuck-at-0. If the wrong cell is addressed,...
Ngày tải lên: 07/11/2013, 20:15
Logic kỹ thuật số thử nghiệm và mô phỏng P11
... paths to ground or power. On average, a node is going to be at logic 0 half the time and at logic 1 half the time. If the node is at logic 0 and is connected to a pullup, a path exists for current ... behavioral model for very low level behavioral devices, namely, the logic gates. Faults such as high-resistance bridging shorts, inside a logic gate or between con- nections to adjacen...
Ngày tải lên: 07/11/2013, 20:15