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Briefing: Independent NASA Test of RTSX-SU FPGAs. RT54SX-S & RTSX-SU Programming Status. RTSX-SU Programming Software Enhancements. Background Higher than normal fallout was reported during initial programming of RTSX-SU devices at customer sites
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Briefing: Independent NASA Test of RTSX-SU FPGAs RT54SX-S & RTSX-SU Programming Status
RTSX-SU Programming Software Enhancements • Background • Higher than normal fallout was reported during initial programming of RTSX-SU devices at customer sites • The fallout was due to an increase in the post-programming ICCA standby value • The measurement fault was shown to be a Silicon Sculptor configuration issue
Icca Measurement FaultRoot Cause • The erroneous ICCA readings were caused by the following two mechanisms: • A low resistance path between VCCA and GND for designs with I/Os configured with power up pull-down resistors. • On the Sculptor programmer, 112 I/Os are connected to VCCA via a 10kΩ resistor. For the case where an I/O is configured with a power up pull-down resistor, a low resistance path exists between VCCA and GND via the 10kΩ resistor on the Sculptor and the power up pull-down resistor of the I/O. • Connection between VPU driver (different power supply driver and Sculptor) and VCCA through a 10kΩ resistor. • Current flows from VCCA into VPU through the resistor connection
ICCA Measurement Fault Solution • Two software changes were implemented to eliminate the causes of the high ICCA measurements: • Turn off the power up pull-down resistor by configuring the bits in the mode shift register so the power up pull-down resistor is disabled. • Note that under normal operating conditions, the power up pull-down resistor turns on only during the power up transient and a customer would not see any high current on a bench setup. • Set VPU = VCCA • No potential difference across the connecting resistor and therefore no current flow.
ICCA Measurement Fix Release Information • The software fixes were implemented, tested and integrated into the V3.85 (DOS)/ V4.48.0 (WIN) release and all subsequent releases of Silicon Sculptor software
MEC Modified New Algorithm • Targets low current dynamic antifuses • Will be released in March ’05 in Sculptor software version 3.87/4.50 • Important Notes: • Sculptor 3.87/4.50 will reject original AFM (pre 6.1 SP1) files • Programming only supported on Silicon Sculptor II
MEC Modified New Algorithm Reliability Study Test Vehicle • Vehicle: MEC RT54SX32S-CQ208B • NASA design(KU1/KU2/KM1/KM2) • Quantity: 300 • Duration: 2000 hours • ATE Pull Points: 24,48,168,500,1000,1500 & 2000 hours • Ambient Temperature: 125°C • Junction Temperature: 148°C • VCCA = 2.75V VCCI = 4.0V • Clock frequency = 8MHz I/O / 32MHz Array • I/O Undershoot = -1V(avg) • Terminated boards will be utilized • Visual LED monitoring at upload and download only– • NOT used as pass/fail criteria
MEC Modified New Algorithm Reliability Study Test Plan • Programming • Devices are serialized • Logs automatically saved for each device • ATE Testing • Full datalogging by serial number of each part at each pull point • Functional results and delay path values logged • DC parametrics not recorded unless device fails functional test • External Burn In House • Outside Vendor RQE (San Jose, CA) • Criteria Burn-In chambers/HP-GPIB power supplies • Voltage monitoring • Full persistence monitoring of voltages with digital oscilloscopes • Datalogging of spikes above a certain threshold (VCCA=3.00V) • STUPID– NASA OLD group provided Software
MEC Modified New Algorithm Reliability Study Test Plan • ATE Test coverage • Same as NASA experiments • Experiment Schedule • Start April 2005 • Completion July 2005 • Updates to be communicated via • Actel White Papers • Presentations • Industry Tiger team meetings