Dale E. Pontius

A 500-MHz multi-banked compilable DRAM macro with direct write and programmable pipelining

This work describes a 500-MHz compiled eDRAM macro offered in a 90-nm logic-based process. The macro architecture is optimized for high bandwidth while enabling compilation in bank and data-word dimensions. A direct write scheme simultaneously improves random bank cycle time and row access time without signal loss. The benefits of ground sensing, reference cells, and bitline twisting was reviewed. A variable stage pipeline extends the macro bandwidth while offering flexibility in clock frequencies. The redundancy system is modified to support direct write and piping. Finally, BIST was enhanced to utilize electrically blown fuses, enabling one-touch test and repair. Hardware results was presented.

A 45nm SOI compiled embedded DRAM with random cycle times down to 1.3ns

A family of embedded DRAMs which are fabricated in 45nm SOI technology is presented. The fast eDRAM has 64 b/BL and achieves a random cycle time of 1.3ns for VDD = 1.00V and typical process. The dense eDRAM has 128 b/BL and operates in multi-bank modes up to 1.67GHz for VDD = 1.0V and nominal process. The staggered - folded BL architecture with BL twisting over both the array and SAs is described as well as a novel wordline timer which generates a 75% duty cycle signal from a 50% duty cycle clock.

A 1.0GHz multi-banked embedded DRAM in 65nm CMOS featuring concurrent refresh and hierarchical BIST

An embedded DRAM macro fabricated in 65 nm CMOS achieves 1.0 GHz multi-banked operation at 1.0 V yielding 584 Gbits/sec. The array utilizes a 0.1 1 mum2 cell with 20 fF deep trench capacitor and 2.2 nm gate oxide transfer gate. Concurrent refresh allows for high availability via a second bank address. At-speed test and repair is accomplished with a new hierarchical BIST architecture. Measured random cycle time exceeds 333 MHz at 1.0 V with functional operation from 750 mV to 1.5 V and densities up to 36.5 Mbits.