6/8/03J. Lajoie - PHENIX Silicon Workshop1 Pixel Ladder, PILOT Issues Physical structure of first pixel layer –FPGA-based PILOT chip readout Show some results from simulation model –Kapton cable bus for parallel pixel chip readout Is a parallel readout structure possible? J. Crandall, J. Hill, J. Lajoie, C. Ogilvie, G.Tuttle, S. Skutnik

6/8/03J. Lajoie - PHENIX Silicon Workshop2 Implementation in PHENIX Laser + 2 pin diodes Dig PILOT GOL Ana PILOT Flash ADC Pilot/control board, one per ladder supplies voltage to readout reads data from each readout sends data out on fiber-optic sets thresholds, masks etc. start with ALICE design, modify to meet PHENIX needs

6/8/03J. Lajoie - PHENIX Silicon Workshop3 FPGA-based PILOT Module: Problem Statement and Goal Read 8 ALICE1 Pixel Chips in Parallel –Keep readout time within PHENIX specification –Minimize readout electronics Transmit Zero-Word Suppressed Data to Optical Chip (GOL) First look at design –Basic functionality only –Does it match to possible rad-hard FPGA?

6/8/03J. Lajoie - PHENIX Silicon Workshop4 PILOT Module Block Diagram 8 ALICE1 PIXEL CHIPS 32-bit Pixel 10MHz 8 chips in parallel PILOT Module GOL 16-bit PILOT 40MHz LVL1 Strobe NEVR (Next Event Read) CE (Chip Enable)

6/8/03J. Lajoie - PHENIX Silicon Workshop5 PILOT Module Functional Operations READ –Read 32bit-word ALICE1 Pixel Data x 256 MHz –Reject zero words –Append word/cycle Address to 32-bit data word (0-255) –Store into FIFO WRITE –Append Pixel Chip Address (0-7) –Write to GOL 16-bit 40MHz Full PHENIX functionality would require these two operations to be asynchronous!

6/8/03J. Lajoie - PHENIX Silicon Workshop6 Readout Timing ALICE1 Read Time: Store 32b Pixel data + 32b Address (overkill!) in FIFO Total Estimated Pixel-Chip Readout w/10% (word) Occupancy & Zero-word Suppression (Note: design occupancy is <1% per channel)

6/8/03J. Lajoie - PHENIX Silicon Workshop7 FPGA Coding Written in VHDL for basic functionality –Read, Zero-suppress, Write to GOL Implement in FPGA Logic –Synthesize VHDL to FPGA architecture (Xilinx) –Implement Triple Modular Redundancy (TMR) TMR for state and critical logic Check match for size, gates, timing etc. of FPGA

6/8/03J. Lajoie - PHENIX Silicon Workshop8 Xilinx FPGA Synthesis Exceeded (BRAM capacity) of XCV600E (~23mm X 23mm, ~660k system gates) Easily fit XCV2000E (~40mm X 40mm, ~2M system gates)  Does not currently meet ladder-physical size constraint, BUT  Use a smaller die and put FIFOs in system logic. Device Xilinx v2000efg680-6 (~40mm X 40mm) Number of Slices: 576 out of % Number of Slice Flip Flops: 633 out of % Number of 4 input LUTs: 1001 out of % Number of bonded IOBs: 276 out of % Number of TBUFs: 512 out of % Number of BRAMs: 32 out of % Number of GCLKs: 2 out of 4 50%

6/8/03J. Lajoie - PHENIX Silicon Workshop9 Functionality and Timing Tests Simulation of read cycle and zero suppression:

6/8/03J. Lajoie - PHENIX Silicon Workshop10 Radiation Tolerance of FPGA’s Development driven by satellite applications Xilinx QPro Series –Guaranteed for 100kRad operation (~9.0 rad/s rate) –SEL Immunity up to LET ~ 125 MeV cm 2 /mg –SEFI Immunity up to LET ~6 MeV cm 2 /mg (with TMR!) –Configuration data can be “scrubbed” –>100kRad possible with “self-annealing” ACTEL Rad-Hard Antifuse (RTSX-S) –Extensive use in industry –SEFI LET Immunity up to ~37 MeV cm 2 /mg (TMR in hardware!) –Antifuse (program once!) –ProASCI (Flash) not fully tested for rad-hard applications Need to more fully absorb test data and match PHENIX requirements

6/8/03J. Lajoie - PHENIX Silicon Workshop11 FPGA-based PILOT Chip Future Work Continue with software simulation Multi-event readout cycle (async. READ/WRITE) Bit-level zero suppression, smaller headers Include ALICE1 and GOL behavioral models into simulation Move on to FPGA hardware, late summer/fall ‘03 Implement Triple Modular Redundancy for state machine logic Radiation Dose Estimates, FPGA evaluation for rad-hard performance Evaluate failure modes, rates.

6/8/03J. Lajoie - PHENIX Silicon Workshop12 Pixel Readout Bus 8 readout chips per ladder, 2 ladders laid end-to-end ladder control pixel chip READOUT CHIP PIXELS DETECTOR 150 to 200µm 290µm 150 to 200µm carbon fiber support cooling passive components Multi-layered kapton ALICE bus 32 signal lines  each chip read-out sequentially  8*25.6  s = 200  s

6/8/03J. Lajoie - PHENIX Silicon Workshop13 Line Density Bus width is ~ 15mm Line pitch= 15mm/(8*32) = 58  m –each output is single-ended Existing busses –D0 (2001) pitch 50  m “fanned” out to 100  m, trace width 7-8  m –D0 (2002) two // cables each with pitch 91  m avoided “fan” –Both made by Dyconex (Swiss), other manufacturers identified Manufacturing problems scale with bus length! Requirements are close to state-of-the-art for production –Our length (~50cm), requirements not unreasonable

6/8/03J. Lajoie - PHENIX Silicon Workshop14 Bonding Chip to Bus READOUT CHIP PIXELS DETECTOR 150 to 200µm 290µm 150 to 200µm carbon fiber supportcooling passive components wire bond density same as ALICE ~ 12mm/32 ~ 375  m

6/8/03J. Lajoie - PHENIX Silicon Workshop15 Parallel Bus Summary Worthwhile considering what limits going to an 8*32 signal bus –allows us to read all eight chips in parallel –time = (15  s + time to write) ~ 40  s Structure of readout bus must match requirements and manufacturing capabilities –Power and ground planes or traces? –Two or four layer bus?

6/8/03J. Lajoie - PHENIX Silicon Workshop16 Backups

6/8/03J. Lajoie - PHENIX Silicon Workshop17 Pilot Internal Structure READ Module WRITE Module 8b-Counter L1a addr NEVR CE cout Count_ enable From ALICE1 To GOL

6/8/03J. Lajoie - PHENIX Silicon Workshop18 Read Module + FIFO (Parallel Operation, Replicated 8x) Read Control Logic X 64b X 256 deep FIFO X (Synchronous) L1a From ALICE1 NEVR CE 64b Data_in addr Rd_enable cout Count_enable 64b Data_out Wr_enable

6/8/03J. Lajoie - PHENIX Silicon Workshop19 FIFO + Write Module (Daisy-Chain Operation, Replicated 8x) 64b X 256 deep FIFO X (Synchronous) 64b Data_out Write Control Logic X Done x Wr_enable L1a Start x Done x-1 Start x+1 16b to MUX empty

6/8/03J. Lajoie - PHENIX Silicon Workshop20 Write Daisy Chain MUX FIFO x-1 FIFO x FIFO x+1 WRITE x-1 WRITE x WRITE x+1 GOL

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