Serial Data Link on

Advanced TCA Back Plane

M. Nomachi and S. Ajimura

Osaka University, Japan

CAMAC – FASTBUS– VME / Compact PCIWhat’s next?

RT2005 Nomachi, M. 2

CAMAC crate

Downsizing (Rack-Crate-Module-Chip-)

CPU

BUS

module module module

RT2005 Nomachi, M. 3

Module

Downsizing (Rack-Crate-Module-Chip-)

Is CPU at right place?Should we have parallel BUS on board?Do we still need crate?

CPU

BUS

FPGA FPGA FPGA

NetworkInterface

Questions

RT2005 Nomachi, M. 4

Functionality of a CPU

• Data readout– Register/memory access– Block transfer

• Data processing– Application dependent

• Network protocol– TCP/IP etc.– It is indispensable function for network DAQ.

CPU sits at the boundary between memory mapped I/O and network

RT2005 Nomachi, M. 5

Rack

Crate

Module

Chip

MemoryMapped

I/O

CPU

Network

DAQ architecture

MemoryMapped

I/O

CPU

Network

CPU

Network

RT2005 Nomachi, M. 6

Rack

Crate

Module

Chip

MemoryMapped

I/O

CPU

Network

DAQ architecture

We choose memory mapped I/O in a crate.

It makes easy to maintain CPU.There were many bad experiences on embedded CPUs.

RT2005 Nomachi, M. 7

Downsizing the interconnections

• Parallel bus on board– Occupy large area– Need many pins

• Serial data link will be a solution– It can be low noise/low power

• Less number of drivers

– It may have longer latency• 1 ns – 100 ns.

• Memory mapped I/O over serial data link.

RT2005 Nomachi, M. 8

SpaceWire

• Remote Memory Access Protocol (RMAP)• SpaceWire was presented by S. Parkes.

– RMAP is a protocol on the SpaceWire standard.

– Register access has large overhead.– Block transfer works almost full speed.– It meets the requirements. Good enough.– PCI express and the other protocol may also

meet the requirements. However, they may use too much logic (x10) for front-end FPGAs.

RT2005 Nomachi, M. 9

Do we need crate?

• Serial data link is very flexible.– System with no crate is possible.

• Functionality of crates:1. Mechanical Housing / Shielding2. Power supply3. Cooling– We need a crate.

• VME– 6U is too small– Power is a problem on VME. -5.2V etc.

RT2005 Nomachi, M. 10

Advanced TCA• Features

(ATCA was presented by B. Martin and S. Dhawan)

– -48V DC power supply and on board DC converter for any voltages required.

– 8U x 280 mm– Dual Star point to point differential connection– No definite protocol.

• VME back plane is for VME protocol. While, ATCA back plane is only defined as 100 ohm differential. Any protocol can use ATCA back plane. ( for example, ATCA for physics instrumentation)

RT2005 Nomachi, M. 11

Read outmodule

Triggermodule

Front-endmodule

DAQ system

Front-end

Pipe-linebuffer

readoutbuffer

Trigger logic

Trigger control

Globaltrigger

Readout control

networkSecondlevel

trigger

CPU

To event builder

RT2005 Nomachi, M. 12

Dual star connection

Triggermodule

Read outmodule

Front-endmodule

Front-endmodule

Front-endmodule

Front-endmodule

Front-endmodule

Asynchronous signals(4 links)•Trigger/Reset•Local trigger/Busy

SpaceWire link(4 links)

CPU(T-kernel)

RT2005 Nomachi, M. 13

There are 4 ports for one channel. One port has one output and one input.

In order to make signal extraction easy,2 ports are used. (SpW uses 2 ports)The other 2 ports are to extend band width. It makes possible to use 4-layers PCBs.

RT2005 Nomachi, M. 14

Trigger module

16 LVDS in16 LVDS out8 NIM in8 NIM out

Power consumption is about 10W

Cyclone EP1C12 for trigger logicCyclone EP1C6 for SpW100Mbps SpW

RT2005 Nomachi, M. 15

500 MHz FADC

Cyclone EP1C6 (cheaper than 40 Euro)Cyclone EP1C12 for router100Mbps SpW (8~9 MB/s from the module)Readout buffer with 128Mb SDRAM waiting second level trigger

8 ch analog inputFADC mezzanine card is developed at KEK (FINESSE format)

Power consumption is About 20W

RT2005 Nomachi, M. 16

ATCA crate

One crate holds 96ch of 500MHz FADCs. Total power is expected to be 260 W.

RT2005 Nomachi, M. 17

Summary

• SpaceWire Remote Memory Access Protocol provides compact and flexible interconnection in a module and inter-module connection.

• Advanced TCA provide dual star LVDS connections. They are good to be applied for DAQ system

• Downsizing may continue.– We might have another solution in the

future.