本文设计了异步LDPC解码器运算通路,利用异步电路减少信号到达时间不一致引起的毛刺和时钟引起的功耗.利用输入数据的统计特性设计了运算通路中的主要运算单元,减少了冗余运算.本文还实现了同步运算通路和基于门控时钟的运算通路作为比较.三种设计采用相近的架构,在0.18μmCMOS工艺下实现相同的功能.仿真结果表明,提出的异步设计功耗最小,相比于同步设计和基于门控时钟设计,分别节省了42.0%和32.6%的功耗.虽然性能稍逊于同步设计,但优于门控时钟设计.其中,同步设计的延时是1.09ns,基于门控时钟的设计延时是1.61ns,而异步设计则是1.20ns.
Asynchronous datapath of LDPC decoder is proposed in this paper. Glitches and redundant computations are de- creased by asynchronous design. Clock tree is replaced by handshake control units. Taking advantages of input data statistical charac- teristic,key arithmetic elements in the datapath are proposed. Two types of datapaths including synchronous design and clock-gating design are also implemented as contrasts. Three designs exploit similar architecture and realize the same function by 0.18/Zm CMOS process. Simulation result shows that the proposed asynchronous design features the lowest power. Compared with the synchronous and clock-gating designs,it saves 42.0% and 32.6% power respectively.Its performance is a little bit worse than the synchronous design, but is better than the clock-gating design. The delay of the synchronous design is 1.09ns, the clock-gating design is 1.61 us, and the proposed design is 1.20ns.