RTSX-S and RTSX-SU Reliability Test Vehicles Daniel K. Elftmann Director Product Engineering Richard Katz Head Grunt Office of Logic Design Igor Kleyner Deputy Grunt Office of Logic Design September 8 th, 2004

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 2 Background  Background  In 2003, some customers reported clusters of failures  Customer failures had some common factors  Stressful designs  I/O and/or power supplies exceeding datasheet limits  Failures occur early in device life  Actel investigation indicated isolated programmed antifuses were failing to a higher impedance state  Industry investigation  Actel working closely with Industry Tiger Team (ITT) led by The Aerospace Corp.  Participants include Lockheed Martin, Boeing, General Dynamics, Northrop Grumman Space Technology, JPL, NASA  A series of experiments are being conducted to investigate the customer failures  Remainder of presentation describes the two different Test Vehicles being used for the following experiments  Industry Tiger Team Design  NASA Test Design

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 3 Industry Tiger Team Design Top Level Block Diagram

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 4 Industry Tiger Team Design 1,146 Stage Slow Ring Oscillator  Synchronized Reset input assures clean startup of slow ring oscillator  Delta Read & Record must be done via frequency measurement  No mechanism to break ring and measure delay directly  Zoom Debug feature  Allows for enhanced isolation of delays during debug only  Long oscillator frequency stabilization time of ~15 minutes at startup

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 5 Industry Tiger Team Design Slow Oscillator Startup

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 6  Independent controls to set Pattern generator toggle rate for internal R-Cells  16 unique patterns possible, with range of toggle rates (more later)  Clock generated via internal 15 stage ring oscillator (~50MHz)  Dedicated Startup Synchronization circuitry for IO_clock domain  IO_Monitor indicates pass/fail  On-chip self-checking circuitry detects and latches detected errors Note: not all errors are detectable by self-test Industry Tiger Team Design 140 Bit I/O Shift Register

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 7 Industry Tiger Team Design Ring Oscillator  Ring Oscillator instantiated twice  1 st drives Array SR, 2 nd drives I/O SR  Additional delay stage inserted in Array oscillator to keep two oscillators out of sync  Ring Oscillators frequency dependent on Temperature & V CCA voltage  Ring Oscillators NOT recommended for flight designs

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 8 Industry Tiger Team Design Shift Enable Control  Independent Shift Enable circuits instantiated in each of the 2 sequential blocks to pace R-Cell toggling  ShiftEnable_n fanout = 16  R-Cell U0 fan out managed via register replication  Both Array shift register & I/O shift register blocks set by same input configuration pin settings:

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 9 Industry Tiger Team Design Pattern Generator

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 10 Industry Tiger Team Design I/O Weave Shift Register  I/O Weave block three modes of operation  Mode 1: I/O Bypass (OE=‘0’ TOG_n=‘X’)  Operates as shift register bypassing the I/Os thru 2-1 multiplexers  No I/Os toggle and are tri-stated

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 11 Industry Tiger Team Design I/O Weave Shift Register  I/O Weave block three modes of operation  Mode 2: I/O Weave (OE=‘1’ TOG_n=‘1’)  Operates as shift register toggling I/O pad at pattern generator defined rate  Signal takes path thru output buffer to the pad and back into input buffer  I/O toggle rate controlled by Pattern Generator

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 12 Industry Tiger Team Design I/O Weave Shift Register  I/O Weave block three modes of operation  Mode 3: All I/O Toggle (OE=‘1’ TOG_n=‘0’)  Simultaneously switches all I/Os from 0 to 1 then 1 to 0  Pattern follows shift register chain enabling pattern checker to detect errors at any point in chain  Register n+1 <= !n  Simultaneous 100% I/O Toggle Rate

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 13 Industry Tiger Team Design 707 Bit Array Shift Register  Array shift register has independent controls to set Pattern generator toggle rate for internal R-Cells  Options for the Pattern Generator identical to I/O Shift Register Pattern Generator  Typical setting for Simultaneous Switching Registers (SSR) set at 12.5%  Clock generated via internal 16 stage ring oscillator (~50MHz)  Dedicated Startup Synchronization circuitry for A_Clock domain  A_Monitor indicates pass/fail  On-chip self-checking circuitry detects and latches detected errors Note: not all errors are detectable by this self-test

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 14 Industry Tiger Team Design Aerospace Experiments 83 parts General Test Project 4b1 Temp = ~40°C VCCA= 2.5V Project 4b2 Temp = ~40°C V CCA = 2.5V ~500 parts Project 7 Temp = ~40°C V CCA = 2.5V Colonel Test 600 hrs RT54SX32S MEC with “old” algo 1000 hrs + RT54SX32S MEC with “old” algo RT54SX32S MEC with “new” algo 330 parts 1000 hrs + 83 parts Project 4b2 Temp = 85°C V CCA = 3.0V Project 4b2 Temp = ~40°C V CCA = 2.5V

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 15 NASA Design Top Level Block Diagram

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 16 NASA Design Header Bd. Clock & Reset Driver  NASA Office of Logic Design (OLD) designed and built solder in card to Burn-in Board (BIB) to provide clock and reset to 8 Devices Under Test (DUT)  Card solders into BIB configuration socket locations  Clocks for DUTs in each column can be controlled to run 180° out of phase  Clocks can be driven up to 64MHz  Jumper selectable clock dividers available on Header Board  HCLK, CLKA, and CLKB frequency independently settable

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 17 NASA Design 1,236 Stage Delay Line  Configuration lines select input to delay line during operation  Synchronized Reset input insures clean startup  Direct delay delta read & record measurement possible via Delay_in  No free running oscillator & related self-heating thermal effects, therefore no startup stabilization issues  Allows for more accurate delay measurements  Zoom feature removed as un-needed, Action Probe circuitry sufficient for debug

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 18 NASA Design 144 Bit I/O Shift Register  Changes  Utilizes HCLK vs. 15 stage internal ring oscillator  Industry Tiger Team design does NOT utilize the HCLK resource  HCLK driven by NASA header board add-on card  Dedicated Reset Synchronization circuitry for HCLK clock domain  Increased fan out of Shift Register Enable nets from 16 vs. 29  Exceeds maximum fan out allowed (24) in Designer Software by 20%  Number of I/Os 143 vs. 139  78 configured for 5V CMOS, remainder 5V TTL; Industry Tiger Team design all TTL

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 19 NASA Design 621 Bit Array Shift Register  Changes  Utilizes CLKA vs. 16 stage internal ring oscillator  CLKA driven by NASA header board add-on card  Increased fan out of Shift Register Enable nets from 16 vs. 29  Exceeds maximum fan out allowed (24) in Designer Software by 20%  Shift register R-Cells manually placed to improve utilization of Long Vertical Tracks (LVT) and Long Horizontal Tracks (LHT)  Array_out added to increase observability at tester  Number of bits 621 vs. 707

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 20 NASA Design Final Design Summary  Utilization Post-Combiner device utilization: SEQUENTIALUsed: 1080 Total: 1080 (100.00%) COMB Used: 1800 Total: 1800 (100.00%) LOGIC Used: 2880 Total: 2880 (100.00%) (seq+comb) IO w/ Clocks Used: 168 Total: 170 (78 CMOS) (89 TTL) CLOCK Used: 2 Total: 2 HCLOCK Used: 1 Total: 1  Fan out  23 nets have fan out of 29  1 net with fan out of 28  Timing Analysis  Maximum frequency 125C, V CCA = 2.25V, V CCI = 4.5V, Speed –1)  Array Clk => 72MHz  IO Clk => 71MHz  Hold time analysis -55C, V CCA = 2.75V, V CCI = 5.5V, Speed –1)  Shortest path slack => 0.51ns  NASA design bounds user applications better than Industry Tiger Team design

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 21 NASA Experiments Project KH1 Temp = 125°C VCCA= 2.75V 300 parts HOT 250 hrs RT54SX32S MEC “Modified New Algo” 300 parts Increasing V CCA /V CCI Voltage Increasing SSO Increasing SSU Increased time Project KC1 Temp = -55°C VCCA= 2.75V 300 parts COLD 250 hrs RT54SX32S MEC “Modified New Algo” 300 parts RTSX32SU UMC Increasing V CCA /V CCI Voltage Increasing SSO Increasing SSU Increased time RTSX32SU UMC Parts to be tested in 500 hour steps Stress levels increased for each step. Voltage, # SSOs, amount of SSU, time Internal circuit loading fixed at 120% of max load Each step is 250 hours of HTOL followed by 250 hours of LTOL Test Protocol

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 22 Appendix: RTSXS-U Test Data

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 23 ITT Design Actel RTSX-SU (UMC) Data set  This data set includes the following for RTSXS-U:  2 sets of experiments were completed (P7, P4B2)  RTOL = Room Temperature Operating Life  TC = Temperature Cycle (-65°C to 150°C)

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 24 ITT Design P7 Data  Configuration Details:  No I/O’s toggle, Array toggle rate = I/O toggle rate = 12.5%  3 monitor pins toggling - Visual readout using LED  Undershoot less than -0.4V

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 25 ITT Design P4B2 Data  Configuration Details:  I/O toggle rate = 50% (70 I/Os), Array toggle rate = 12.5%  ~2V undershoot

Paper #172 Wednesday, September 8th, 2004MAPLD 2004: RTSX-S and RTSX-SU Reliability Test Vehicles 26 NASA/Actel Team  NASA  Igor Kleyner  Rich Katz  Actel  Manish Babladi  Marco Cheung  Paul Louris  Minal Sawant  Dan Elftmann