TTCM

TTCM is a Trigger, Timing and Control Module for VMEDAQ system. It is a 6U VME64x slave module. TTCM has onboard 40 MHz clock generator that is used for clock source for TTC bus. TTCM has NIM level LEMO inputs for spill and 7 trigger signals and 32 ECL/LVDS inputs for trigger signals. Two NIM level LEMO outputs are software programmable.

Front Panel Interface

TTC Bus Output

TTC bus output provides clock, spill, trigger and reset LVDS signals. It is compatible with VMEDAQ specification.

LEDs

• 1 (red) - lights on spill when data readout is enabled
• 2 (yellow) - blinks on blocked triggers (dead time)
• 3 (green) - blinks on triggers being read out

Inputs

• NIM1..NIM7 - Trigger inputs, NIM standard, 5 ns minimum
• SPILL - external sync signal, positive logic. Readout enabled with logic one on this input.
• LVDS1..LVDS32 - Trigger inputs, LVDS or ECL, 5 ns minimum

Outputs

• OUT1 - NIM, spill output
• OUT2 - NIM, BRIC clock
• P12 internal connector - aux. TTC output

TTCM VME Interrupt Lines

• IRQ1 - data read XOFF input
• IRQ2 - spill output
• IRQ5 - data read request output

VME Registers

• Detailed description of TTCM VME Registers

VME Data Format

• TTCM Raw Data Format

Trigger Cable

For use with TQDC-16, special ribbon twisted pair cable is supplied with 34-pin connector on one side and four 10-pin connectors on other side. One cable connects four TQDC-16 modules with TTCM.

Input Aggregation

Trigger inputs are combined after shaping and delay by OR scheme. 40 inputs are reduced to 4 trigger lines. Logic OR is performed this way (trigger line = input OR input ...):

• ST = LVDS1
• TQDC1 = LVDS6 | LVDS10 | LVDS14
• TQDC2 = LVDS18 | LVDS22 | LVDS26 | LVDS30
• NIM = NIM1 | ... | NIM7

Trigger Logic Delay

Measured delay from NIM input to TTC bus output: min. 530 ns, max. 580 ns. Due to 20 MHz sampling the delay is varied by 50 ns. this applies to TTCM firmware 1.0.10604

TTC Bus

See TTC for details.

P12 TTC Connector

Internal P12 connector is duplicating the front-panel TTC output. Even signal pin positive.

TTCM Block Diagram

TTC Output Signals

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Logic VME TTC