Serial Data Link on Advanced TCA Back Plane M. Nomachi and S. Ajimura Osaka University, Japan CAMAC...
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Transcript of Serial Data Link on Advanced TCA Back Plane M. Nomachi and S. Ajimura Osaka University, Japan CAMAC...
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. 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.