Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information.

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Differential Power Analysis

In this paper, we propose a set of rules for consistent estimation of the real performance and power features of the flip-flop and master-slave latch structures. A new simulation and optimization approach is presented, targeting both high-performance and power budget issues. The analysis approach reveals the sources of performance and power-consumption bottlenecks in different design styles. Certain misleading parameters have been properly modified and weighted to reflect the real properties of the compared structures. Furthermore, the results of the comparison of representative master-slave latches and flip-flops illustrate the advantages of our approach and the suitability of different design styles for high-performance and low-power applications.

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Comparative analysis of master-slave latches and flip-flops for high-performance and low-power systems

Design and experimental evaluation of a new sense-amplifier-based flip-flop (SAFF) is presented. It was found that the main speed bottleneck of existing SAFF's is the cross-coupled set-reset (SR) latch in the output stage. The new flip-flop uses a new output stage latch topology that significantly reduces delay and improves driving capability. The performance of this flip-flop is verified by measurements on a test chip implemented in 0.18 /spl mu/m effective channel length CMOS. Demonstrated speed places it among the fastest flip-flops used in the state-of-the-art processors. Measurement techniques employed in this work as well as the measurement set-up are discussed in this paper.

/pdf/improved-sense-amplifier-based-flip-flop-design-and-1l8icizbke.pdf

Improved sense-amplifier-based flip-flop: design and measurements

A semiconductor memory device includes a memory cell array having a first group of main blocks, a second group of main blocks and redundancy blocks replacing the first group of main blocks or the second group of main blocks, a repair logic suitable for enabling a replacement signal when one or more of the second group of main blocks are defective, a control logic suitable for generating an address for the second group of main blocks in response to a dedicated command for access to one or more of the second group of main blocks, and an address decoder suitable for selecting one or more of the redundancy blocks based on the address for the second group of main blocks when the replacement signal is enabled.

Semiconductor memory device and method of operating the same

An efficient methodology for detecting and rejecting faulty integrated circuits with embedded memories utilizing stress factors during the manufacturing production testing process. In the disclosed embodiment of the invention, a stress factor is applied to an integrated circuit having built-in-self-test (BIST) circuitry and built-in-self-repair (BISR) circuitry. A BIST run is then performed on a predetermined portion of the integrated circuit to detect a set of faulty memory locations. The results of this first BIST run are stored. A second condition is applied to the die and a second BIST run is executed to generate a second set of faulty memory locations. The results of the second BIST run are stored and compared with the first result. If the results differ, the integrated circuit is rejected. Thus, a methodology for screening out field errors at the factory is disclosed using BIST/BISR circuitry.

Redundancy analysis for embedded memories with built-in self test and built-in self repair

This paper describes a hybrid latch-flipflop (HLFF) timing methodology aimed at a substantial reduction in latch latency and clock load. A common principle is employed to derive consistent latching structures for static logic, dynamic domino and self-resetting logic.

Flow-through latch and edge-triggered flip-flop hybrid elements

A semiconductor memory array with Built-in Self-Repair (BISR) includes redundancy circuits associated with failed row address stores to drive redundant row word lines, thereby obviating the supply and normal decoding of a substitute addresses. NOT comparator logic compares a failed row address generated and stored by BISR circuits to a row address supplied to the memory array. A TRUE comparator configured in parallel with the NOT comparator simultaneously compares defective row address signal to the supplied row address. Since NOT comparison is performed quickly in dynamic logic without setup and hold time constraints, timing impact on a normal (non-redundant) row decode path is negligible, and since TRUE comparison, though potentially slower than NOT comparison, itself identifies a redundant row address and therefore need not employ an N-bit address to selected word-line decode, redundant row addressing is rapid and does not adversely degrade performance of a self-repaired semiconductor memory array. By providing redundancy handling at the predecode circuit level, rather than at a preliminary address substitution stage, access times to a BISR memory array in accordance with the present invention are improved.

Register-based redundancy circuit and method for built-in self-repair in a semiconductor memory device

The AMD-K6 MMX-enabled processor is plug-compatible with the industry-standard Socket 7 and is binary compatible with the existing base of legacy X86 software. The microarchitecture is based on an out-of-order, superscalar execution engine using speculative execution. High performance and compact die size are achieved by using self-resetting, self-timed and pulsed-latch circuit design techniques in custom blocks and placed-and-routed blocks of standard cells. The 162 sq. mm die is fabricated on a 0.35-/spl mu/m, five-layer metal process with local interconnect. It is assembled into a ceramic pin grid array (PGA) using C4 flip-chip mounting. The processor functions at clock speeds up to 266 MHz.

Circuit techniques in a 266-MHz MMX-enabled processor

An active power supply filter effectively eliminates power supply noise using a resistive element and a capacitive element coupled at a node, and a switch with a control terminal controlled by the node. The active power supply filter is suitable for high frequency operation of a voltage-controlled oscillator (VCO) in a phase-locked loop (PLL) of a high-speed microprocessor. The active power supply filter removes VCO noise that would otherwise create jitter that reduces the effective clock cycle of the microprocessor. The active power supply filter is similarly useful in applications other than VCOs, PLLs, and microprocessors in which removal of substantial amounts of noise from the power supply is useful.

Active power supply filter

This sixth-generation X86 instruction-set compatible microprocessor implements a set of multimedia extensions. Instruction predecoding to identify instruction boundaries begins during filling of the 32 kB two-way set associative instruction cache after which the predecode bits are stored in the 20 kB predecode cache. The processor decodes up to two X86 instructions per clock, most of which are decoded by hardware into one to four RISC-like operations, called RISC86 Ops, whereas the uncommon instructions are mapped into ROM-resident RISC sequences. The instruction scheduler buffers up to 24 RISC86 operations, using register renaming with a total of 48 registers. Up to six RISC86 instructions are issued out-of-order to seven parallel execution units, speculatively executed and retired in order. The branch algorithm uses two-level branch prediction based on an 8192-entry branch history table, a 16-entry branch target cache and a 16-entry return address stack. The 10.18/spl times/15.38 mm/sup 2/ die contains 8.8M transistors. The chip is in 0.35 /spl mu/m CMOS using five layers of metal, shallow trench isolation, and tungsten local interconnect.

Donald A. Draper

Papers

Flow-through latch and edge-triggered flip-flop hybrid elements

Register-based redundancy circuit and method for built-in self-repair in a semiconductor memory device

Circuit techniques in a 266-MHz MMX-enabled processor

Active power supply filter

An X86 microprocessor with multimedia extensions