1. An MTCMOS Design Methodology and Its Application to Mobile Computing
Samsung, Tohoku University in Japan
ISLPED’03

2. MTCMOS / VTCMOS/ dual Vt
Introduction
Mobile device requires high performance and low standby power
High performance
MTCMOS / VTCMOS/ dual Vt
High performance
Low Vt
Low performance
Low Vt

3. to maintain performance
Preliminaries
MTCMOS
Process VDD Vt leakage exp
to maintain performance
virtual ground bounce
channel width of CCS

4. Preliminaries
Problem: stored data in sleep mode

5. Design issues(1) Current of CCS Mutual exclusive pattern
Consider timing
Cluster based partially exclusive pattern
T=RC α VC/I , I α W
Average Current Method (ACM)
Different designs same average ground bounce

6. Design issues(2) Complementary pass-transistor flip flop 1.Clock low
2.Clock high
Edge trigger
3.Sleep mode

7. Floating input problem
IP in SOC always awake in sleep mode

8. Floating prevention circuit (FPC)
Insert tri-state buffer & holder

9. MTCMOS power management
PMB is embedded for
mobile computing
Date-preserving
RC of VGND

10. RTL include PMB (SC & SCB)
Design flow
RTL include PMB (SC & SCB)
CPFFs & FPCs insert
Power estimation & use ACM

11. Result
Chip features
Leakage is 6000 times smaller than non-MTCMOS

12. Conclusion Cut-off switches sizing and insertion
CPFF preserve the data
FPC prevent short-circuit current
PMB integrated
Three orders of reduction of leakage