# Presentation: 470004

## Switching for BTeV Level 1 Trigger

***Jinyuan Wu***
***(For the BTeV Collaboration)***

## Level 1 vertex trigger architecture

**30 station pixel detector**

## DAQ From M. Bowden’s Talk

## BTeV Trigger (From M. Wang’s Talk)

## Data From Pixel, Organized in Highways

- This is DCB.

- The PDCB and DCB look similar.

- There are 10 sub-racks for pixel system.

- There are 8 cables per sub-rack.

- Each cable has 12 fibers.

**80 cables, 960 fibers**
**10 cables/hwy**

- Each card sees 1⁄4 station, 12 cards/sub-rack.

- Each cable goes to one highway.

## Optical Receivers to Segment Finder

**Optical Receivers, 10 cards/hwy**

**Pre-processors, 32 cards/hwy**

**Segment Finders, 32 cards/hwy**

**TO Farmlet**** **

**TO L1 Buffer:**

**From PDCB**

## Optical Receiver

**IN:**** 12 fibers **
**1 cable/card**

**OUT:**** 16 cables/card**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Rate/cable:**
**2.5 Gb/s x 12/16**
**= 2.5 Gb/s x 3/4**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Rate/fiber:**
**2.5 Gb/s**

**Optical Receivers, 10 cards/hwy, 80 cards total**

## Pre-processor

**Rate/cable:**
**2.5 Gb/s x 12/16 x 5/4**
**= 2.5 Gb/s x 15/16**
**LVDS 4 pairs/cable**
**<<585 Mb/s per pair**

**Pre-processors, 32 cards/hwy, 256 cards total**

**IN from Optical Receivers**
**5 cables/card**

**OUT to Segment Finders:**** **
**4 cables/card**

**OUT to L1 Buffers:**** **
**4 cables/card**

**Rate/cable:**
**2.5 Gb/s x 12/16**
**= 2.5 Gb/s x 3/4**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Rate/cable:**
**2.5 Gb/s x 12/16 x 5/4**
**= 2.5 Gb/s x 15/16**
**LVDS 4 pairs/cable**
**<<585 Mb/s per pair**

## Segment Finder

**Rate/cable:**
**2.5 Gb/s x 12/16 x 5/4**
**= 2.5 Gb/s x 15/16**
**LVDS 4 pairs/cable**
**<<585 Mb/s per pair**

**Segment Finders, 32 cards/hwy, 256 cards total**

**IN from Segment Finders:**** **
**4 cables/card**

**OUT to DSP Farmlets:**** **
**4 cables/card**

**Rate/cable:**
**2.5 Gb/s x 12/16 x 5/4**
**= 2.5 Gb/s x 15/16**
**LVDS 4 pairs/cable**
**<<585 Mb/s per pair**

## Optical Receivers to Segment Finder

**IN:**** 120 fibers **
**10 cables/hwy**

**OR_PP:**** 160 cables**

**Optical Receivers, 10 cards/hwy**

**Pre-processors, 32 cards/hwy**

- Ch: (1/120)
- BCO: (1/8)

- Ch: (1/10)
- BCO: (1/8 x 1/16)

**Segment Finders, 32 cards/hwy**

- Ch: (1/2)
- BCO: (1/8 x 1/16 x 5/4)

- Ch: (all)
- BCO: (1/8 x 1/16 x 5/4 x 2/4)

**TO Farmlet**** **
**128 cables**

**PP_SF:**
**128 cables**

**TO L1 Buffer:**** 128 cables**

## Short Compares

|  | TDR | New |
| --- | --- | --- |
| L1 Switching Function | To Farmlet: Yes
To L1 Buffer: No | To Farmlet: Yes
To L1 Buffer: Yes |
| L1 Trigger Switch Hardware | Yes ($800K) | No ($0) |
| Bandwidth from Preprocessor to Segment Finder | 2.8 x 
Input bandwidth | 1 x 
Input bandwidth |
| Number of cards/hwy | OR: 10
PP: 120 (60, 30?)
SF: 56 (28?) | OR: 10
PP: 32
SF: 32 (64?) |
| Optical Receiver | Simple, FPGA not even needed | Need FPGA |
| Latency | Minimum | Longer, Need Study |

## To Do and Questions

**Optical receiver.**
**Latency budget.**
**Last stations.**
**Reduce switching in DAQ stages?**
**Further absorb segment finder into preprocessor?**

## End

## Pixel data readout

**time-stamp expansion**

**time ordering**

**clustering algorithm**

**xy table lookup**

**Notes:**
-describe how data gets from pixel stations to vertex trigger hardware
-each half station ~125 FPIX2 ROC’s
-all FPIX2’s send data in parallel via high speed serial liinks to DCB’s
-DCB merges multiple input streams into fewer output streams
-data size per hit ~3bytes, translates to ~40GB/s data rate for full pixel detector
-DCB tacks on 13-bit chip ID increasing data rate to ~70GB/s
-data transmitted from collision hall to counting room via high speed optical links
	o where they are received by pixel processors that perform a number of functions

## Optical Receiver

**Optical Receivers, 80 cards full system**

**12 fibers in **
**1 cable/card**

**8 highways/card**
**16 cables/card**

- 0,64,...

- 8,72,...

- 16,80,...

- 24,88,...

- 32,96,...

- 40,104,...

- 48,112,...

- 56,120,...

**LVDS 4 pairs/cable **
**LVDS 8 pairs/card/hwy**
**<470 Mb/s per pair**

## The 4x4 Cable Bundle

## Switching in the Processing Stages

**Optical Receivers, 80 cards full system**

**12 fibers in **
**1 cable/card**

**8 highways/card**
**16 cables/card**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Pre-processors, 32 cards/hwy**

**160 cables/hwy**
**640 pairs/hwy**

**80 cables**
**960 fibers**

**5 cables**
**20 pairs/card**

**To L1**
**Buffer**

**To Segment**
**Finder**

**Cable bundle**
**4 x 4**

- Ch: (1/80)
- BCO: (all)

- Ch: (1/80)
- BCO: (1/8 x 1/2)

- Ch: (1/4)
- BCO: (1/8 x 1⁄2 x 1⁄4 )

**Segment Finders,**
**40 cards/hwy**

**4 cables/card**

- Ch: (all)
- BCO: (1/8 x 1⁄2 x 1⁄4 x 1/5)

**To DSP**
**Farmlet**

## To L1 Buffer, Etc.

**Pre-processors, 32 cards/hwy**

**5 cables**
**20 pairs/card**

**To L1**
**Buffer**

**To Segment**
**Finder**

**Cable bundle**
**4 x 4**

- Ch: (1/4)
- BCO: (1/8 x 1⁄2 x 1⁄4 )

**Segment Finders,**
**40 cards/hwy**

**4 cables/card**

- Ch: (all)
- BCO: (1/8 x 1⁄2 x 1⁄4 x 1/5)

**To DSP**
**Farmlet**

**4 cables/card**

- Ch: (all)
- BCO: (1/8 x 1⁄2 x 1⁄4 x 1/5)

- L1 Buffer

- SF

- SF

- SF

- SF

## In One Highway:

**Optical Receivers, 10 cards/hwy**

**12 fibers in **
**1 cable/card**

**16 cables/card**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Pre-processors, 32 cards/hwy**

**160 cables/hwy**

**10 cables/hwy**
**120 fibers/hwy**

**5 cables**

**To L1**
**Buffer**

**To Segment**
**Finder**

- Ch: (1/10)
- BCO: (1/8)

- Ch: (1/10)
- BCO: (1/8 x 1/16)

- Ch: (1/2)
- BCO: (1/8 x 1/16 )

**Segment Finders,**
**40 cards/hwy**

**4 cables/card**

- Ch: (all)
- BCO: (1/8 x 1/16 x 2/5)

**To DSP**
**nodes**

## In One Highway:

**Optical Receivers, 10 cards/hwy**

**IN:**** 12 fibers **
**1 cable/card**

**OUT:**** 16 cables/card**
**LVDS 4 pairs/cable**
**<470 Mb/s per pair**

**Pre-processors, 32 cards/hwy**

**160 cables/hwy**

**10 cables/hwy**
**120 fibers/hwy**

**IN:**** 5 cables**
**OUT:**** 8 cables**

**To L1**
**Buffer**

**To Segment**
**Finder**

- Ch: (1/10)
- BCO: (1/8)

- Ch: (1/10)
- BCO: (1/8 x 1/16)

- Ch: (1/2)
- BCO: (1/8 x 1/16 )

**Segment Finders,**
**64 cards/hwy**

**IN:**** 4 cables**

- Ch: (all)
- BCO: (1/8 x 1/16 x 4/8)

**To DSP**
**nodes**

## Optical Receivers to Segment Finder

**IN:**** 120 fibers **
**10 cables/hwy**

**OR_PP:**** 160 cables**

**Optical Receivers, 10 cards/hwy**

**Pre-processors, 32 cards/hwy**

- Ch: (1/120)
- BCO: (1/8)

- Ch: (1/10)
- BCO: (1/8 x 1/16)

**Segment Finders, 64 cards/hwy**

- Ch: (1/2)
- BCO: (1/8 x 1/16 x 1/8)

- Ch: (all)
- BCO: (1/8 x 1/16 x 1/8 x 2/4)

**TO Farmlet**** **
**256 cables**

**PP_SF:**
**256 cables**

## BTeV trigger overview

- L1 rate reduction: ~100x

- L2/3 rate reduction: ~20x

- 4 KHz