Glitch reduction in digit-serial recursive filters using retiming

In this work, we study how retiming can be used to reduce glitches in digit-serial recursive filters. It is a well known fact that glitches can make up a large portion of the dynamic power consumption in digital systems. Digit-serial recursive systems contain registers that can be retimed to reduce the amount of glitches. A second-order digit-serial LDI allpass filter has been implemented to verify this statement. It is shown that retiming can reduce the power consumption with about 20% for small digit-sizes without affecting the throughput of the filter. We also show that introducing a large number of registers in the filter structure will increase the current consumption. This trade-off, between reducing the amount of glitches and the increase in the number of registers, is also considered in this work.