Some features of V1495

Shiuan-Hal ,Shiu

Everything in this document is not final decision!

V1495

(“times 4”)

μ

x

hodoscope

y

hodoscope

discriminator

level shifter

level 1 v1495

level 2 v1495

triggersupervisor

TRIGGER

level 1 v1495

level 1 v1495

level 1 v1495

We are using 5 v1495 to form into trigger decision system. Each Lv1 v1495 will send 32 bits data to Lv2 v1495. 4 Lv1 v1495s will handle in upper Y’s, upper X’s, lower Y’s, lower X’s

The I/O of V1495

• Lv1 v1495: 3 ECL/LVDS input ports, 1 LVDS output port and 1 ECL output port. Each port have 32 channels

• Lv2 v1495: 4 ECL/LVDS input ports, 1 LVDS output port and 1 ECL output port. Each port have 32 channels

• All Lv1 LVDS output ports are defined to send data to Lv2 v1495. ECL output data will send to latch card.

FPGA block diagram

PLL

Delay &internal pulse width

control

Look Up Table(pipeline mode)

40MHz Local clock

Sampling unit 1

250MHz/4 Phases

Sampling unit 2

Sampling unit 3

Sampling unit 4

retiming memory

Lv1 x96Lv2 x128

250MHz

Lv1 512*9*8*3Lv2 512*9*8*4

Multiplexer

The block diagram here only shows the main function for trigger establishing.

Data output

Data input

One channel

Internal pulse structure• After FPGA sampling the input signal edge

transition, all the timing information of input signal will be retiming first then stored into the memory in FPGA.

• Then we can adjust the signal delay and pulse width before the signal go into the Look up table part.

delay

Adjustable Pulse width

Why we need adjustable delay?

• The main purpose of adjustable delay is to avoid using bunch of cable to delay signal and eliminate the different hardware delay in different ports.

• We need make sure all the signals go into the look up table part at the same time.

Timing information• Without any look up tables, signals from

v1495 input to output cost 82ns.• All the logic in look up tables are going to

several steps pipeline process to determine the data pattern.

• Each steps cost 4ns, and a typical logic need using 5 steps which need about 20ns to process.

• 1 v1495 will cost total 82+(# of step)*4 ns

What is pipeline stepStage

1LUT

Stage3

LUT

Stage2

LUT

Stage4

LUT

Stage5

LUT

Data input

CLOCK

Data output

if(A( 0)='1' AND B( 0)='1' AND D( 0)='1' )then F_temp_lv1_0( 0)<='1'; else F_temp_lv1_0( 0)<='0'; end if; if(A( 0)='1' AND B( 0)='1' AND D( 8)='1' )then F_temp_lv1_0( 1)<='1'; else F_temp_lv1_0( 1)<='0'; end if;

if(F_temp_lv1_0( 0)='1' OR F_temp_lv1_0( 1)='1' OR F_temp_lv1_0( 2)='1' OR F_temp_lv1_0( 3)='1')then F_temp_lv2_0( 0)<='1'; else F_temp_lv2_0( 0)<='0'; end if;if(F_temp_lv1_0( 4)='1' OR F_temp_lv1_0( 5)='1' OR F_temp_lv1_0( 6)='1' OR F_temp_lv1_0( 7)='1')then F_temp_lv2_0( 1)<='1'; else F_temp_lv2_0( 1)<='0'; end if;

Stage1Stage2

Resources we have already used about the v1495 FPGA

• Without any look up table logic we have already used 5493/20060 (27%)logic elements, and (512*9*8*3+4096=114688) 114688/294912(39%) memory and ½(50%) PLL each v1495.

• From a simple muon track simulation in bend plane, we found there are almost 1400 track conditions will appear for a positive muon. It means 2800 track combinations need to deal in one v1495, and in worst case may cost about 9000 logic elements. V1495 now still have 14567 logic element, I think it is enough.

Highlights of v1495

• The V1495 now have a dead time free, 1ns signal resolution. (still have some bug will cause 4ns jittering.)

• We can adjust all channel’s delay from 12ns to 128ns in 1ns step and adjust internal pulse width from 4 to 64 ns in 4ns step.

• The v1495 now didn’t synchronize with any clock, but we can add this.