New Record Interface for Modular Register Map Firmware

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New Record InterfaceforModular Register Map
Firmware

• (a work in progress)
• Eric Björklund

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Current Status

• Strawman Design is essentially complete
• e.g. Mozarts Requiem
• Brookhaven has begun coding on the Event Receiver
  driver/device support.
• Design points are being vigorously discussed

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Previous (APS) Monolithic Record Style

• One record per EVR
• erevent records mapped events to actions
• One record per EVG
• egevent records defined sequences
• Adding hardware features required adding record
  fields
• Significant mismatch between APS-style records
  and Modular Register Map.

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Proposed Interface

• Replace specialized monolithic records with
  standard EPICS record types (bi, bo, mbbi, mbbo,
  ai, ao, longin, longout)
• Record fields in the previous model are replaced
  by individual records.
• Features can be added/removed without needing to
  recompile/rebuild all your IOCs.

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Basic Addressing Scheme

• VME_IO addressing is used.
• Record function is determined by record type,
  signal number, and parameter.

C0 S5 _at_PULSER_DELAY
Set (a0) or Read (ai) Pulser Delay
EVR Card 0
Pulser 5
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Modification to Addressing Scheme

• Object Oriented
• Record function is determined by record type,
  device type, signal number, and parameter.
• Reflected in EVG section (but not EVR section)
• Possibility of creating custom device support for
  event system features.

DTYP EVR Pulser
Object is an Event Receiver Pulser
C0 S5 _at_DELAY
Set (a0) or Read (ai) Pulser Delay
EVR Card 0
Pulser 5
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Example EVG Sequencer

• Three Objects
• Sequences
• Sequence Events
• Sequence RAMs

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Sequences

• Collection of Sequence Events (up to 2048)
• Each sequence has a unique identifying number.
• There may be many (more than 2) sequences defined.

DTYP EVR Sequence
Object is anEvent Generator Sequence
C0 S2 _at_SEQ_UNITS
Select Time Units for Sequence Delays (mbbo)
EVG Card 0
Sequence Number 2
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Sequence Event

• An object, but also a property of a sequence.
• Sequence Events have Names
• Names must be unique within a sequence
• Same name can appear in different sequences
• Sequence event is defined by 2 4 records
• EVENT_CODE (longout)
• EVENT_TIME (ao)
• EVENT_ENABLE (bo)
• EVENT_PRIORITY (longout used to resolve
  collisions)

DTYP EVR Sequence
Object is anEvent Generator Sequence
C0 S2 _at_EVENT_CODE CycleStart
Set Event Code for CycleStart Event
Event Name
Event Belongs to Sequence Number 2
EVG Card 0
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Sequence RAM

• System-Wide Functions
• Operating Mode (Single or Multi Sequence)
• Update Mode (Accumulate Changes or Immediate)
• Switch RAMs
• RAM-Specific Functions
• Set Trigger Mechanism
• Set Repeat Mode
• Load Sequence Into RAM
• Start/Stop Sequence RAM

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Sequence RAM Operating Mode

• Single-Seq Mode
• Like the old Alternate Mode
• Treats the card as if there were only one
  sequencer
• Sequence updates are written to the inactive RAM
• RAMs switch at end of current sequence.
• Sequence RAM 0 is the virtual sequence RAM
• Multi-Seq Mode
• Nothing automatic happens
• You have complete control of the sequence RAMs

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Sequence RAM Update Mode

• Only applicable when operating mode is
  Single-Seq
• Immediate
• Any change to the sequence takes place
  immediately after the end of the current cycle.
• Accumulate
• Changes to the sequence do not take effect until
  they are told to.

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Sequence RAM Switch Record

• Only applicable when operating mode is
  Single-Seq and update mode is Accumulate
• Mechanism that signals that sequence changes
  should take effect.

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Active Design Questions

• Human-Centric Vs. Hardware-Centric Interface
• Atomic change issues
• e.g. Output Port Assignments
• What is useful?
• e.g Do We Need 2 Event Mapping RAMs?
• Device Support Vs. Asyn
• Multiple-Driver Issues
• e.g. Linux CompactRIO EVR Drivers,Old New
  Register Map
• Intra-Record Dependencies
• e.g. Sequencer RAMsTime Conversion