Communication & Control H.Evans Columbia U. Overview of FRC Functions: Road Info STCs,TFCs Device Independent Data Format SCL STCs,TFCs,ZVC (c.f. MBT) L1 Info: to other boards L2 Info: to Buffer Control SCL Init L3 Buffers All (c.f. VRB) Define Standard L3 Buffer Unit Buffer Protocol Status/Mon. All Init / Busy / Error Monitoring Registers (c.f. MBT)

L3 STC Clus-Buff (r-phi) G-Link Conv (CFT) L1CTT FRC (road) FRC (cntrl) Status L3 FRC Road-Buff FRC (buff-ctrl) Roads + L1-SCL L1 Info Buffer Control L1 / L2 SCL Hub SCL Mezz FRC (scl) Init / Busy / Error G-Link Conv (SMT) SMT Fiber STC (clus) 1 evt STC (cntrl) Status L3 STC Clus-Buff (z) L3 STC Clus-Buff (r-phi) STC (assoc) L3 STC Assoc-Buff ZVC 16 evt 16 evt L3 TFC Fit-Buff TFC (format) TFC (fit) TFC (cntrl) Status 16 evt TFC (xmit) L2CTT MBT

Road Data Format Control Info Required with each word Valid Data End of Event CLK 3 Extra Bits for each word transferred

L1CTT Data Format See M.Martin: http://d0server1.fnal.gov/www/protocols/

L1CTT Glossary (Abridged) Header P/N Some Trks w/ Pos/Neg Pt No. Ptx No. of Trks in Pt Bin x Data S Sign of Trk Pt Bin Pt Bin Number (0-3) Ext. Pt Bin-1 (1.5-3 GeV) A-Offset Bin-2 (3-5 GeV) A-Offset Bin-3 (5-10 GeV) Pt-Info Bin-4 (10- GeV) Pt-Info H/L Trk assoc w/ Hi/Lo PS Clust Err Transmission Errors R PS Clust assoc in adjacent sect PSC RA Rel. Addr of PS Clust Rel  H-Layer Fiber Number Is Isolated Track eI Isolated Electron Trk Adr Address of 4.5o wedge of Trk

Serial Command Link Steal as much as possible from MBT L1 Accept see MBT TDR (ver. 5 - 5/24/99) http://macdrew.physics.umd.edu/dzero/trigger/mbt.html L1 Accept L1_TURN, L1_BX, L1_QUAL sent to: STCs, TFCs, ZVC(?) as 1st element of Road Data FRC Buffer Control to request next Buffer L2 Accept L1_TURN, L1_BX, L3_TRAN_NO sent to: FRC Buffer Control to initiate Buffer Transfer

SCL (cont.) SCL Init Sequence Command Implementation 1) FRC Rec Init from Hub mezzanine 2) FRC Send Init to all Card User pin 3) FRC INIT_ACK to Hub mezzanine 4) FRC Clear L1/L2_ERROR mezzanine 5) All Receive Init from FRC User pin 6) All Raise Local Busy VME stat reg 7) All Start Init Sequence wait until all Inputs are clear send Init Done signal 8) FRC Poll all Local Stat Regs VME or Wait for local init_ack’s User pin 9) FRC Clear INIT_ACK mezzanine Have to be ready for SCL Init on any 132 ns SCL word !

Buffers and Control Steal from VRB / VRBC Possible System: see ESE-SVX-950719 (7/1/99) http://www-ese.fnal.gov/eseproj/index/svxii/svxii.htm Possible System: FRC(buff) acts as Buffer Manager for all L3 Buffer Units in system sends same control signals to all Units basically: Write to Buffer i L1 Acc Read from Buffer j L2 Acc All buffer number management at FRC control signals derived from L1/L2 SCL decouples SCL from rest of system (aside from road data) Use same L3 Buffer Unit on all cards simplifies I/O use L3 Buffer Unit on FRC ? Control Protocol = a subset of VRBC

L3 Buffer Unit Data Source Buffer Controller Data Buffer (MPM)  Message Input FIFO 16 evt Busy/Error Data Pointer Route & Count Cmd/Addr Decode RW Data Enable/Reset/Busy/Error Count/Ovfl Route & Count Enable/Reset/Busy/Error C/O Data Status Format/Xmit VME VBD Output FIFO FIFO full Addr Error Count / Status

VRB Buffer Protocol Messages: 12+2(?) bit Field on Ext Ctrl Port Bits 11..8 Type 7..0 Value Control 1..0 Valid,CLK

Buffer Protocol (cont.) Status in VRB: open collector TTL on J5/6 OR of all modules

STT Control / Status Fast Status User pins Monitoring VME Regs Event-by-Event Comm. w/ Trigger Lines to FRC are OR of all boards SCL Init / Restart from FRC Busy / Error / Init Ack to FRC Each board must define Actions for Init / Restart (w/in guidelines of SCL Init Sequence) conditions for Busy / Error Monitoring VME Regs Steal from MBT (?) Use Standard Monitoring Registers same memory maps

FRC To Do List (from BU) Check for Truncation Scheme Biases Define Road Info Data Format Decide Where Reformatting of L1CTT Info will be Done Decide on Communications Medium Identify SCL Info Needed Define Data to L3 Define Buffer Control Protocol Define Monitoring Data / Monitoring Control Long List of Internal FRC Decisions… Done First Pass Still Pending