PhLOM (TRIG) Manual

PhLOM Front Panel Connectors Description

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 trigger

Inputs

NIM1 - Trigger input, NIM standard, 5 ns minimum
SPILL - external sync signal, positive logic. Readout enabled with logic one on this input.
P2 LVDS1..LVDS32 - Trigger inputs, LVDS or ECL, 5 ns minimum

Outputs

P4 internal connector - aux. TTC output, diff. ECL
P3 ECL1..ECL32 - Aux outputs, diff. ECL. LVDS1 is fan-out to ECL1..ECL15

Switches

bsw1, bsw0 - serial minor. Serial = 4+minor
bsw15:bsw11 - GA4:GA0

GA 3, Serial 4:

bsw0..bsw7: 1 1 0 0 0 0 0 0
bsw8..bsw15: 0 1 1 0 0 1 1 1

VME Interrupt Lines

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

VME Registers

Detailed description of PhLOM/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

TTC Bus

TTC connector pinout

pin pair	signal	description
1, 2	spill	Trigger and data readout enable
3, 4	parity	Odd parity of spill and trigger signals
5, 6	trigger	Trigger signal
7, 8	clock	41.667 MHz clock signal
9, 10	ground	TTC bus signal ground

Even signal pin positive.

Spill, trigger and parity signals have width 50 ns and are synchronous to clock.

Connector: 2.54 mm 2x5 (10 pins).

Connector part numbers: AMP - 1658621-1

Signal Timing

measurement		min	typ	max
clock frequency			41.666667 MHz ±0.001%
spill, parity, trigger	setup time, ns		8.5	10.0
spill, parity, trigger	hold time, ns	5.0	6.0

Timing provided by design TTCM v2.0 firmware rev.8512

1 ns step

CLK  ___/^^^^^^^^^\_________/^^^^^^^^^\_________/^^^

TRIG ________XXXXXXX^^^^^^^^^^^^^XXXXXXX__________...

                    | setup |hold|

TTC 2.0 Timecode Extension

Spill signal is used as a gate for data acquisition. Trigger signal is used only when spill signal is active.

In order to provide TAI timecode to modules an extension of TTC standard is proposed, TTC 2.0.

With spill signal low, trigger line become an encoded serial data channel, 40 Mbps data rate. Timecode information is transmitted serially using 8b10b encoding and K28.5 comma symbol as idle code. Big endian byte order. A sequence of data coded forms a frame.

TAI timecode is encoded as TAI 64-bit Timestamp.

Frame Type 1: Timecode

Frame type 1 transmission time: 25 ns * 20 words * 10 bit = 5 µs. The moment of beginning of first bit of frame corresponds to TAI timecode data being transferred.

Byte
0	Frame type
1	TAI seconds [39:32]
2	TAI seconds [31:24]
3	TAI seconds [23:16]
4	TAI seconds [15:8]
5	TAI seconds [7:0]
6	TAI nanoseconds [29:22]
7	TAI nanoseconds [21:14]
8	TAI nanoseconds [13:6]
9	TAI nanoseconds [5:0], flags[1:0]
10	spill_id[31:24]
11	spill_id[23:16]
12	spill_id[15:8]
13	spill_id[7:0]
14	reserved
15	reserved
16	CRC32[31:24]
17	CRC32[23:16]
18	CRC32[15:8]
19	CRC32[7:0]

TAI - International Atomic Time
flags[3:0] = {time_valid, ptp_wr_mode, ptp_mode, ntp_mode}
CRC32 use Ethernet 802.3 polinom

TTC WhiteRabbit

P4 TTC Connector

Internal P12 connector is duplicating the front-panel TTC output. Even signal pin positive. Signal level: differential ECL

pin pair	signal	description
1-10	reserved	don't use
11, 12	trigger	trigger signal
13, 14	spill	Trigger and data readout enable
19, 20	ground	signal ground

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