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ISUAL Mass Memory. Robert Abiad. Outline. Description Requirements Interfaces Block Diagram Usage Scheme Parts Development Status. Description. 2.6 GBits organized as 64 M x 40 bits 32 bit data word after EDAC
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ISUAL Mass Memory Robert Abiad
Outline • Description • Requirements • Interfaces • Block Diagram • Usage Scheme • Parts • Development Status NCKU UCB Tohoku Mass Memory R. Abiad
Description • 2.6 GBits organized as 64 M x 40 bits • 32 bit data word after EDAC • 7 bit Error Correction Code per word corrects all single bit errors and detects all double bit and some multiple bit errors. • Base device is Samsung K4S560832A-TL1H 256 Mbit chip organized as 32M x 8bits. NCKU UCB Tohoku Mass Memory R. Abiad
Requirements • Store data from Imager at 8M pixels/s data rate • Store data from Array Photometer at 20k samples/s x 32 channels/sample = 640k channels/s • Store data from Spectrophotometer at 10k samples/s x 6 channels/sample = 60k channels/s • Read telemetry data at 1.6 Mb/s • Allow read/write from DPU • Allow read/write from DCM NCKU UCB Tohoku Mass Memory R. Abiad
Mass Memory Interfaces IDC/ Mass Memory ACQUIRE Imager 12 DATA CLK DATA 2 SP CLK 2 STB 2 CTS Telemetry DATA-1 AP CLK DATA-2 DATA CLK RTS STB DATA DPU CMD0 CMD1 CLK 32 DATA DCM ADDR 26 MBUSY R/W 2 NCKU UCB Tohoku Mass Memory R. Abiad
Priorities • Imager • Memory Refresh • Telemetry • Array Photometer • Fast Spectrophotometer • Slow Spectrophotometer • DPU • DCM NCKU UCB Tohoku Mass Memory R. Abiad
Mass Memory Block Diagram Imager Data Interface 32MB SDRAM 32MB SDRAM AP SP DPU 32MB SDRAM 32MB SDRAM DCM Level Shift TLM 32MB SDRAM 32MB SDRAM Address Interface 32MB SDRAM 32MB SDRAM Level Shift 32MB SDRAM 32MB SDRAM NCKU UCB Tohoku Mass Memory R. Abiad
Usage Scheme A A • Circular buffers • Fill on trigger • M Pretrigger • N Posttrigger • Buffer switch Buffer Allocation M Trigger N B Buffer Allocation NCKU UCB Tohoku Mass Memory R. Abiad
SAMSUNG SDRAM • Latch up immune up to 82 MeV/(mg/cm²) • Radiation hardened to 17-40 kRad total dose • Radiation study done by Innovative Concepts, Inc. • No total dose issues • SEU rate of ~100 events/day • Uncorrectable error rate of ~4/day NCKU UCB Tohoku Mass Memory R. Abiad
Development Status • Engineering unit designed and built • Actel 85% done • Board powered up • Currently debugging • First tests to be done with DPU • Interface tests planned with Imager and DCM NCKU UCB Tohoku Mass Memory R. Abiad
Schematics Page 1 NCKU UCB Tohoku Mass Memory R. Abiad
Schematics Page 2 NCKU UCB Tohoku Mass Memory R. Abiad
Schematics Page 3 NCKU UCB Tohoku Mass Memory R. Abiad
Schematics Page 4 NCKU UCB Tohoku Mass Memory R. Abiad