Draft 1.6 June 14, 1998 Level 1 Calorimeter Trigger to Global Trigger Interface Description of Data: The calorimeter trigger electronics generates four 20 bit phi maps and one 10 bit phi map. These maps are called M(20 bits), G(20 bits), E(20 bits), X(20 bits) and Y(10 bits). Their nature is described below: M is 20 phi strips (one bit for each strip) with energy grater that about 120 MeV. This corresponds to a minimum ionizing particle (MIP) traversing the calorimeter. G is 20 phi strips (one bit for each strip) with energy greater than about 160 MeV. This corresponds to a high-deposit MIP or a low energy gamma or electron in the calorimeter. E is 20 phi strips (one bit for each strip) with energy greater than about 500 MeV. This corresponds to a high energy gamma or electron. X is 20 phi strips in the Forward end cap (one bit for each strip) with energy greater than about 120 MeV. Y is 10 phi strips In the backward end cap and barrel (one bit for each strip) with energy greater than about 2000 MeV. This corresponds to a Bhabha. Description of Geometry: The phi maps will have their bits centered at the following phi positions. For M,G,E and X phi maps; Bit 0 = 4.5 degrees 10 = 184.5 degrees 1 = 22.5 degrees 11 = 202.5 degrees 2 = 40.5 degrees 12 = 220.5 degrees 3 = 58.5 degrees 13 = 238.5 degrees 4 = 76.5 degrees 14 = 256.5 degrees 5 = 94.5 degrees 15 = 274.5 degrees 6 = 112.5 degrees 16 = 292.5 degrees 7 = 130.5 degrees 17 = 310.5 degrees 8 = 148.5 degrees 18 = 328.5 degrees 9 = 166.5 degrees 19 = 346.5 degrees For Y phi map; Bit 0 = 13.5 degrees 5 = 193.5 degrees 1 = 49.5 degrees 6 = 229.5 degrees 2 = 85.5 degrees 7 = 265.5 degrees 3 = 121.5 degrees 8 = 301.5 degrees 4 = 157.5 degrees 9 = 337.5 degrees Description of Signal Levels: The signals will be transmitted as differential PECL signals. Positive logic is used. ATT xx41 series of differential drivers and receivers will be used. Description of Connector, Cable and Pins: There are ten cables. Each cable, about 20 feet long, will carry 2 bits of phi data for M,G,E,X and 1 bit of phi data for Y. Cable one will carry phi strips 0 and 1 for 20 bit phi maps and strip 0 for 10 bit phi map. Cable two will carry phi strips 2 and 3 for 20 bit phi maps and strip 1 for 10 bit phi map. And so on for 10 cables. The connector will be the 3m type 0.1 x 0.1 inch pin grid. There are 20 pins on each connector in two rows of 10 pins each. The arrow on the connector defines pin 1; pin 2 is opposite and pin 3 is adjacent. The pins for cables one are listed below: pin 1 M1 + pin 2 M1 - pin 3 M2 + pin 4 M2 - pin 5 G1 + pin 6 G1 - pin 7 G2 + pin 8 G2 - pin 9 E1 + pin 10 E1 - pin 11 E2 + pin 12 E2 - pin 13 X1 + pin 14 X1 - pin 15 X2 + pin 16 X2 - pin 17 Y1 + pin 18 Y1 - pin 19 nc pin 20 nc - There will be female sockets on the cables at the Global Trigger end to mate with the males on the Global input cards. The cables themselves will be supplied by the EMC trigger group. Description of Timing: It is assumed that the phase of the clocks in the Calorimeter trigger and global trigger crates are adjusted to within 20 ns of each other. This requires that the decoding of sync commands be treated the same in the calorimeter and global crates. Commands use 12 bits (ZS CCCCC DDDDD) of serial data. ZX is 01 and is the start of a command string. CCCCC is 5 bits of command. DDDDD is 5 bits of data (token). The sync signal will be issued on the 14 clock 60 after the start of a command string. The data is transmitted over the cables at clock 8. Transmitted data is delayed by 1/2 of the clock 8 period and remains valid for one clock 8 period. This ensures that the data will be valid on the rising edge of clock 8 at the receiver. The transmitted data is also delayed by 0 to 8 clock 8 periods depending on the configuration. This delay is used to time the arrival of the calorimeter data to the drift chamber data at the global trigger. Timing is shown below: __ __ __ __ __ Tran. Clock 8 __| |__| |__| |__| |__| |__ _ _____ _____ _____ _____ ____ Tran. Data _|_____|_____|_____|_____|____ _ _____ _____ _____ _____ ____ Cable Data _|_____|_____|_____|_____|____ __ __ __ __ __ Rec. Clock 8 __| |__| |__| |__| |__| |__ For test purposes, the StartPlayback command signal is used to simulataneously start the sending and receiving of data in the two systems. The first calorimeter data word will be sent on the first Clock 8 falling edge on or following the 14 clock 60 after the start of the StartPlayback command. The global trigger will start to record data on the Clock 8 rising edge on or following the 18 clock 60 after the start of the StartPlayback command.