written 6.7 years ago by | • modified 6.5 years ago |
Subject :- VLSI Design
Topic :- MOS Circuit Design Styles
Difficulty :- Medium
written 6.7 years ago by | • modified 6.5 years ago |
Subject :- VLSI Design
Topic :- MOS Circuit Design Styles
Difficulty :- Medium
written 6.6 years ago by |
The Shift registers are normally having group of flip-flops. Flip-flop is a 1 bit memory cell. In shift register the flip-flops are controlled by the clock. The number of flip-flops in shift register represent the number of bits used in it. When clock pulse is high data bit is enter into the first flip-flop in the shift register and the data is shifted to the other flip-flop during each clock pulse. The shifting is done by two ways, one is serial shifting and another one is parallel shifting. The following fig.1 shows the master slave flip-flop and based shift register.
The following fig.2 represents the one of the flip- flop model namely Power PC Style(PPCFF). It is fastest and high quality structure and have a short direct path and low power clock load.
Registers | Numbers of gate used | Delay(ns) | Power ($\mu$ W) | Power delay product(J) ($*e^{-15}$) |
---|---|---|---|---|
SISO | 8 | 0.338 | 2.221 | 0.7506 |
SIPO | 12 | 0.38(Q1), 20.38(Q2), 40.38(Q3), 60.34(Q4) | 2.221 | 0.8439, 45.2339, 89.6839, 134.015 |
PISO | 12 | 0.340 | 3.1 | 1.054 |
PIPO | 8 | 0.338(Q1), 0.338(Q2), 0.338(Q3), 0.338(Q4) | 2.91 | 0.9835, 0.9835, 0.9835, 0.9835 |