22-MAY-2003
 

cf. http://www.pa.msu.edu/hep/d0/ftp/l1/framework/andor_terms/
 

Review: And-Or Terms

• The L1 TFW currently implements 256 Hardware And-Or Input Terms

• Each of the 128 L1 Specific Triggers may require one or more And-Or Terms
• COOR specifies a set of And-Or Terms that must be HI
•        and another set of And-Or Terms that must be LOW
• The remainder of the And-Or Terms do not participate

• All 128 L1 Specific Trigger decisions are evaluated for each Beam X

New: P-Terms

• Two sets of 48 Pseudo And-Or Input Terms are being added to the L1 TFW
• These are NOT additional physical inputs to the L1 TFW.
• Formed by fixed combinations of Hardware And-Or Input Terms.
• The state of each P-Term is computed by the L1 TFW for each BeamX

• The Lower 48 P-Terms are combinations

of the lower 128 Hardware And-Or Terms (#0-127).
• The Upper 48 P-Terms are combinations

of the upper 128 Hardware And-Or Terms (#128-255).
• No P-Term definition can ever combine a mixture

of upper (above #128)  and lower (below #127) Hardware And-Or Terms
• The current layout of And-Or Input Terms was explicitely designed to take

this limitation into account given the P-Term requirements known at that time.
• And-Or Input Terms can still be rellocated by moving cables

and updating COOR configuration files.

• P-Term definitions are arbitrary logical combinations

of their corresponding 128 Hardware And-Or Input Terms.
• The P-Term are implemented by the L1 TFW FPGA Firmware.
• The logical combinations making the P-Terms is NOT dynamically programmable.
• These definitions can NOT be changed by COOR from Run to Run.

 
• The Trigger Board must specify the 2 sets of 48 P-Term definitions in advance
• MSU can compile new Firmware to implement these P-Term definitions.
• Once the Firmware is configured into the TFW, the P-Term are frozen.

Numbering Convention:

• The P-Terms are handled by COOR and TCC

as extension of And-Or Term resources.
• P-Terms will use the And-Or Term indices

directly above the current And-Or Terms (#0-255).

• The first set of 48 P-Terms is numbered #256-303 = Lower P-Terms.
• Defined as arbitrary but fixed combinations of And-Or Terms #0-127.

• The second set of 48 P-Terms is numbered #304-351 = Upper P-Terms.
• Defined as arbitrary but fixed combinations of And-Or Terms #128-255.

 

Caution: hidden level of indirection

• P-Term logical combination of Hardware And-Or Input Terms is fixed...
• BUT meaning of And-Or Terms used by a P-Term COULD vary from run to run.
• Changing the meaning of an underlying Hardware And-Or Input Term

would change the effective meaning of the P-Terms

• This needs to be carefully managed by COOR and the Trigger Meisters