Self-timed design with dynamic domino circuits

Journal ArticleWe introduce a simple hierarchical design technique for building high-performance self-timed components using dynamic domino-style circuits. This technique is useful for building handshaking style functional blocks and for self-timed data path components. We wrap the dynamic domino circuit in a wrapper that communicates using a request/acknowledge protocol and mediates the precharge/ evaluate cycle of the dynamic logic. We apply standard bundled delay matching for completion detection but add an early completion feature that can signal completion if function validity can be determined from the output value. The circuit overhead required for this early-acknowledge feature is relatively small, but can provide measurable speedup in some situations. We call this approach semi-bundled delay (SBD)

Self-timed circuits using DCVSL semi-bundled delay wrappers

Journal ArticleWe present a technique for generating robust self-timed completion signals for general dynamic datapath circuits. The wrapper circuit is based on our previous domino semi-bundled delay (SBD) circuits, but uses DCVSL circuits in the wrapper for higher performance. We describe the basic SBD-DCVSL building blocks in the template with respect to their circuit structures and operational behavior. These DCVSL SBD circuits show better performance, exhibit reduced overhead, and require reduced operating margins for the matched delay compared with the domino version. The DCVSL wrapper can also identify a class of delay faults in the data path

Self-Time Circuit Size Optimization For An Input Data Distribution

The analysis is based on the Logical Effort (LE). The LE model used in this work was extracted from SPICE simulation for the TMSC 0.18um process. The performance and energy dissipation of circuits implemented with this approach is 13% and 16% respectively better than circuits designed with previously proposed approaches