Actel

About: Actel is a based out in . It is known for research contribution in the topics: Antifuse & Field-programmable gate array. The organization has 364 authors who have published 402 publications receiving 12674 citations.

Circuits for preventing breakdown of low-voltage device inputs during high voltage antifuse programming

Abstract: A circuit for isolating a first low-voltage circuit mode from a second circuit node which carries high programming voltages during programming of user-programmable interconnect elements includes a novel two input NAND gate having one input structure configured from high voltage devices connected to the second circuit node. The other input of the NAND gate is a control input for the isolation device and is connected to a low-voltage logic signal which is high when the signal from the high programming voltage node is to be passed through to the low-voltage node and low when the low-voltage node is to be isolated from the high programming voltage node. The output of the NAND gate is connected to the first low-voltage circuit node.

Single event upset and hardening in 0.15 /spl mu/m antifuse-based field programmable gate array

Abstract: The single event effects and hardening of a 0.15 /spl mu/m antifuse FPGA, the AX device, were investigated by beam test and computer simulation. The beam test showed no permanent damage mode. Functional failures were observed and attributed to the upsets in a control logic circuit, the startup sequencer. Clock upsets were observed and attributed to the single event transients in the clock network. Upsets were also measured in the user flip-flop and embedded SRAM. The hardening technique dealing with each upset mode is discussed in detail. SPICE and three-dimensional mixed-mode simulations were used to determine the design rules for mitigating the multiple upsets due to glancing angle and charge sharing. The hardening techniques have been implemented in the newly fabricated RTAXS device. Preliminary heavy-ion-beam test data show that all the hard-wired hardening solutions are working successfully.

Central processor architecture implementing deterministic early condition code analysis using digit based, subterm computation and selective subterm combination

Abstract: A central processor architecture implementating a deterministic, digit based, subterm computation and selective subterm combination early condition code analysis mechanism to provide for the early determination of the condition code that will be returned upon normal execution of a condition code setting instruction is described. The early condition code is returned sufficiently early to be combined with a branch mask to substantially reduce if not eliminate the need to interlock an immediately following conditional branch instruction. A wide variety of condition code setting instructions are handled by the deterministic condition code analysis mechanism of the present invention by implementing the mechanism to determine condition codes by the generation of digit subterms of the operand data accompanying condition code setting instruction and then combining the digit subterms in a predetermined manner selected based on the specific condition code setting instruction being executed. Branch decision analysis is performed by inclusion of the branch decision mask as a subterm selectively combined with the condition code subterms.

ESD protection device for antifuses with top polysilicon electrode

Abstract: The present invention is directed to providing an electrostatic discharge ("ESD") protection cell for use in an integrated circuit device including antifuses. The ESD protection cell is formed simultaneously with the antifuses that it protects and provides protection from ESD during the fabrication of the antifuses. The concept is to use thin undoped or doped polysilicon on top of antifuse material as a block etching mask for the formation of the ESD protection cells by using common etching techniques. This polysilicon mask is placed where the antifuses will be and not where the ESD protection cells will be. The polysilicon mask is then merged with a top polysilicon electrode during later processing. During the block etching process, the antifuse material layer is compromised in the region about the ESD protection cells. Where the antifuse material layer is an O--N--O sandwich, the top oxide and nitride layers may be etching during the block etching process leaving the thin bottom oxide layer and some or no residual bottom oxide of the ONO composite antifuse material layer for forming the ESD protection cell. Since etching into the bottom oxide of the ONO composite antifuse material layer will not degrade, but will enhance the ESD protection capability of the ESD protection cell, it is perfectly acceptable to also etch the bottom oxide layer as well as long as proper process control is allowed. The ESD protection cell may be used with antifuses having diffusion or polysilicon type bottom electrodes and polysilicon top electrodes. An advantage of this structure is its ability to be fabricated at high temperature for improved film characteristics and reliability.

Apparatus and method for initializing an integrated circuit device and activating a function of the device once an input power supply has reached a threshold voltage

Abstract: An apparatus for generating a function activation signal to activate a function in an integrated circuit device comprises a power-on circuit receiving a power input and initializing and generating a test activation signal, a test circuit receiving the test activation signal and generating a test result signal, and a threshold decision circuit receiving the test result signal and generating the function activation signal. The test circuit models a function of the integrated circuit device and generates the test result signal when the power input has reached a sufficient voltage to perform the function of the integrated circuit device. The threshold decision circuit generates the function activation signal if the test result signal indicates the power input has reached a sufficient voltage to perform the function of the integrated circuit device.