Dennis Thomas Cox

VLSI performance compensation for off-chip drivers and clock generation

A major problem in VLSI system design is controlling off-chip driver characteristics and skew in clock generation as process parameters, temperature, and supply voltage vary. A control circuit methodology has been developed that senses the relative performance of a CMOS chip and transmits a digitally encoded state to off-chip driver and clock generation circuits to control their operating characteristics

A 0.2 /spl mu/m 1.8 V SOI 550 MHz 64 b PowerPC microprocesser with copper interconnects

A 64 b PowerPC RISC microprocessor is incorporated in a 0.2 /spl mu/m CMOS technology with copper interconnects and multi-threshold transistors and next into a silicon-on-insulator (SOI) version of the same technology. Some architectural changes improve CPI, including doubling the L1 instruction and data caches to 128 kB and adding a 256 kB L2 directory. The total transistor count increased from 12 M to 34 M.

A 660 MHz 64b SOI processor with Cu interconnects

The 64b PowerPC RISC microprocessor previously described is migrated from a 0.22 /spl mu/m SOI technology to a 0.18 /spl mu/m SOI technology. Key features of the 0.77 scaled 1.5 V technology are 0.08 /spl mu/m NFET channel lengths, 7 layer Cu metallization with low-/spl epsiv/ dielectric, low dose SOI substrate for improved material quality and productivity, and local interconnect. Dual gate oxide provides high I/O voltage compatibility. As this chip is a migration only 6 levels of metal and stacked devices for high voltage I/O were used.