Test Generation and Design-for-Testability Based on Acyclic Structure with Hold Registers

We present a method of test generation for acyclic sequential circuits with hold registers. A complete (100% fault efficiency) test sequence for an acyclic sequential circuit can be obtained by applying a combinational test generator to all the maximal time-expansion models (TEMs) of the circuit. We propose a class of acyclic sequential circuits for which the number of maximal TEMs is one, i.e, the maximum TEM exists. For a circuit in the class, test generation can be performed by using only the maximum TEM. The proposed class of sequential circuits with the maximum TEM properly includes several known classes of acyclic sequential circuits such as balanced structures and acyclic sequential circuits without hold registers for which test generation can be also performed by using a combinational test generator. Therefore, in general, the hardware overhead for partial scan based on the proposed structure is smaller than that based on balanced or acyclic sequential structure without hold registers.

加压素—2拮抗剂对肝硬变时水处理障碍的治疗和诊断潜能

水潴留和稀释性低钠血症是肝硬化的并发症,患者具有腹水或外周水肿,产生的原因是肝硬化时机体游离水的清除能力受损,主要是肾脏加压素活性增加,其作用于集合管上的加压素—2受体,调节肾小管对水的通透性,减少水份的清除。这样,从理论上讲,对抗加压素的作用,可以减轻水潴留。