As opposed to the USBee , Salae , Logicport and al the other wannabe's : this is a board from a real logic analyser
picture 1 : the board : 68 channels , 400 MHz state , 2GHz timing , 4 Megasamples per channel. 5 of these boards can be synced up using special cables and interconnect blocks. the flatcable top right is used as a timing aligner while the white connectors above and below the heatsink go form board to board to carry the trigger qualifier signals.
picture 2 : the input stage. the signals come in over the ribbon coax cables 9 gthe flatcabels coming out of this board are actually a bundle of coax cables ) and go into a termination chip . these chips contain the fast comparators with programmable threshold and hysteresis. the bigger chips contain a fifo that brings out the captured data over a slower but wider bus.
picture 3 : the trigger processors. these are big asic's that essentially contain a simplistic custom processor. this processor runs in lockstep with the incoming data and executes the trigger conditions. these monsters can do very complex triggering they handshake amongst each other and talk to their counterparts on expander boards to make essentially a VLIW processor. you can do things like-find pattern p or pattern q, wait 3 clockticks ,if pattern y is detected wait1 clocktick and see of pattern z comes by. then trigger. if no patterny comes by but pattern p restarts : trigger.
these machines can also trigger on glitches, pulses that are too short , too long or on misaligned pulses ( like setup and hold time violations in respect to the clock )
picture 4 : the custom memory controller that handles the sdram. built in (for that time) very expensive FPGA's. depending on the board version you can have 4 , 16 or 32 meg ram. it's a matter of loading different fpga code. i suspect part of the advanced timing processor also sits in the fpga's. depending on what module you run in the LA software they load different fpga config files...
These boards were , new ( 10 years ago) about 32.000 $ ... i have 3 of these in my analyser. (16702B). over the weekend i will upgrade my analyser to a 16900A at which point is will show a more detailed teardown of the entire machine...