Module: OrigenJTAG::TAPController

Included in:
Driver
Defined in:
lib/origen_jtag/tap_controller.rb

Overview

Provides methods specifically for controlling the state of the TAP Controller

Constant Summary collapse

STATES =

Map of internal state symbols to human readable names

{
  reset:          'Test-Logic-Reset',
  idle:           'Run-Test/Idle',
  select_dr_scan: 'Select-DR-Scan',
  capture_dr:     'Capture-DR',
  shift_dr:       'Shift-DR',
  exit1_dr:       'Exit1-DR',
  pause_dr:       'Pause-DR',
  exit2_dr:       'Exit2-DR',
  update_dr:      'Update-DR',
  select_ir_scan: 'Select-IR-Scan',
  capture_ir:     'Capture-IR',
  shift_ir:       'Shift-IR',
  exit1_ir:       'Exit1-IR',
  pause_ir:       'Pause-IR',
  exit2_ir:       'Exit2-IR',
  update_ir:      'Update-IR'
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#state ⇒ Object (readonly) Also known as: current_state

Returns the current state of the JTAG TAP Controller



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# File 'lib/origen_jtag/tap_controller.rb', line 26

def state
  @state
end

Instance Method Details

#idle ⇒ Object

Forces the state to Run-Test/Idle regardless of the current state.



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# File 'lib/origen_jtag/tap_controller.rb', line 330

def idle
  log 'Force transition to Run-Test/Idle...'
  # From the JTAG2IPS block guide holding TMS high for 5 cycles
  # will force it to reset regardless of the state, let's give
  # it 6 for luck:
  6.times { tms!(1) }
  # Now a couple of cycles low to get it into idle
  2.times { tms!(0) }
  update_state :idle
end

#pause_dr ⇒ Object

Goto Pause-DR state then exit back to Run-Test/Idle

This method can be nested inside of a shift_dr block to transition into the Pause-DR state and then back to Shift-DR

Examples:

Trandition into Pause-DR

# State is Run-Test/Idle
jtag.pause_dr do
  # State is Pause-DR
end
# State is Run-Test/Idle

Switching between Shift-DR and Pause-DR

# State is Run-Test/Idle
jtag.shift_dr do
  # State is Shift-DR
  jtag.pause_dr do
    # State is Pause-DR
  end
  # State is Shift-DR
end
# State is Run-Test/Idle


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# File 'lib/origen_jtag/tap_controller.rb', line 138

def pause_dr
  validate_state(:idle, :shift_dr)
  log 'Transition to Pause-DR...'
  if state == :idle
    tms!(1)  # => Select-DR-Scan
    update_state :select_dr_scan
    tms!(0)  # => Capture-DR
    update_state :capture_dr
    tms!(1)  # => Exit1-DR
    update_state :exit1_dr
    tms!(0)  # => Pause-DR
    update_state :pause_dr
    yield
    log 'Transition to Run-Test/Idle...'
    tms!(1)  # => Exit2-DR
    update_state :exit2_dr
    tms!(1)  # => Update-DR
    update_state :update_dr
    tms!(0)  # => Run-Test/Idle
    update_state :idle
  else  # shift_dr
    tms!(1)  # => Exit1-DR
    update_state :exit1_dr
    tms!(0)  # => Pause-DR
    update_state :pause_dr
    yield
    log 'Transition to Shift-DR...'
    tms!(1)  # => Exit2-DR
    update_state :exit2_dr
    tms!(0)  # => Shift-DR
    update_state :shift_dr
  end
end

#pause_ir ⇒ Object

Goto Pause-IR state then exit back to Run-Test/Idle

This method can be nested inside of a shift_ir block to transition into the Pause-IR state and then back to Shift-IR

Examples:

Trandition into Pause-iR

# State is Run-Test/Idle
jtag.pause_ir do
  # State is Pause-IR
end
# State is Run-Test/Idle

Switching between Shift-IR and Pause-IR

# State is Run-Test/Idle
jtag.shift_ir do
  # State is Shift-IR
  jtag.pause_ir do
    # State is Pause-IR
  end
  # State is Shift-IR
end
# State is Run-Test/Idle


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# File 'lib/origen_jtag/tap_controller.rb', line 286

def pause_ir
  validate_state(:idle, :shift_ir)
  log 'Transition to Pause-IR...'
  if state == :idle
    tms!(1)  # => Select-DR-Scan
    update_state :select_dr_scan
    tms!(1)  # => Select-IR-Scan
    update_state :select_ir_scan
    tms!(0)  # => Capture-IR
    update_state :capture_ir
    tms!(1)  # => Exit1-IR
    update_state :exit1_ir
    tms!(0)  # => Pause-IR
    update_state :pause_ir
    yield
    log 'Transition to Run-Test/Idle...'
    tms!(1)  # => Exit2-IR
    update_state :exit2_ir
    tms!(1)  # => Update-IR
    update_state :update_ir
    tms!(0)  # => Run-Test/Idle
    update_state :idle
  else # :shift_ir
    tms!(1)  # => Exit1-IR
    update_state :exit1_ir
    tms!(0)  # => Pause-IR
    update_state :pause_ir
    yield
    log 'Transition to Shift-IR...'
    tms!(1)  # => Exit2-IR
    update_state :exit2_ir
    tms!(0)  # => Shift-IR
    update_state :shift_ir
  end
end

#reset ⇒ Object

Force state to Test-Logic-Reset regardless of the current state



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# File 'lib/origen_jtag/tap_controller.rb', line 343

def reset
  log 'Force transition to Test-Logic-Reset...'
  # JTAG reset
  6.times { tms!(1) }
end

#shift_dr(options = {}) ⇒ Object

Goto Shift-DR state then exit back to Run-Test/Idle

This method can be nested inside of a pause_dr block to transition into the Shift-DR state and then back to Pause-DR

Examples:

Trandition into Shift-DR

# State is Run-Test/Idle
jtag.shift_dr do
  # State is Shift-DR
end
# State is Run-Test/Idle

Switching between Pause-DR and Shift-DR

# State is Run-Test/Idle
jtag.pause_dr do
  # State is Pause-DR
  jtag.shift_dr do
    # State is Shift-DR
  end
  # State is Pause-DR
end
# State is Run-Test/Idle


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# File 'lib/origen_jtag/tap_controller.rb', line 52

def shift_dr(options = {})
  options = {
    start_state: :idle,   # Allowed start states: :idle, :select_dr_scan, :update_ir, :update_dr
    end_state:   :idle    # Allowed end states: :idle, :update_dr
  }.merge(options)

  if options[:start_state] == :idle  # allow for pause_dr state also if called from pause_dr block
    validate_state(:idle, :pause_dr)
  elsif options[:state_state] == :select_dr_scan
    validate_state(:select_dr_scan, :pause_dr)
  elsif options[:state_state] == :update_dr
    validate_state(:update_dr, :pause_dr)
  elsif options[:state_state] == :update_ir
    validate_state(:update_ir, :pause_dr)
  end
  log 'Transition to Shift-DR...'
  if state == :idle || state == :select_dr_scan || state == :update_ir || state == :update_dr
    # Non-pause states
    unless state == :select_dr_scan
      tms!(1)  # => Select-DR-Scan
      update_state :select_dr_scan
    end
    tms!(0)  # => Capture-DR
    update_state :capture_dr
    tms!(0)  # => Shift-DR
    update_state :shift_dr
    if options[:write]
      msg = "Write DR: #{options[:write]}"
    elsif options[:read]
      msg = "Read DR: #{options[:read]}"
    else
      msg = 'DR Data'
    end
    log msg, always: true do
      yield
      log 'Transition to Run-Test/Idle...'
      if @last_data_vector_shifted
        @last_data_vector_shifted = false
      else
        tms!(1)  # => Exit1-DR
        update_state :exit1_dr
      end
    end
    tms!(1)  # => Update-DR
    update_state :update_dr
    if options[:end_state] == :idle
      tms!(0)  # => Run-Test/Idle
      update_state :idle
    end
  else # :pause_dr
    tms!(1)  # => Exit2-DR
    update_state :exit2_dr
    tms!(0)  # => Shift-DR
    update_state :shift_dr
    yield
    log 'Transition to Pause-DR...'
    tms!(1)  # => Exit1-DR
    update_state :exit1_dr
    tms!(0)  # => Pause-DR
    update_state :pause_dr
  end
end

#shift_ir(options = {}) ⇒ Object

Goto Shift-IR state then exit back to Run-Test/Idle

This method can be nested inside of a pause_ir block to transition into the Shift-IR state and then back to Pause-IR

Examples:

Trandition into Shift-IR

# State is Run-Test/Idle
jtag.shift_ir do
  # State is Shift-IR
end
# State is Run-Test/Idle

Switching between Pause-IR and Shift-IR

# State is Run-Test/Idle
jtag.pause_ir do
  # State is Pause-IR
  jtag.shift_ir do
    # State is Shift-IR
  end
  # State is Pause-IR
end
# State is Run-Test/Idle


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# File 'lib/origen_jtag/tap_controller.rb', line 195

def shift_ir(options = {})
  options = {
    start_state: :idle,   # Allowed start states: :idle, :select_ir_scan
    end_state:   :idle    # Allowed end states: :idle, :update_ir, :select_dr_scan
  }.merge(options)
  if options[:start_state] == :idle
    validate_state(:idle, :pause_ir)
  else
    validate_state(:select_ir_scan, :pause_ir)
  end
  log 'Transition to Shift-IR...'
  if state == :idle || state == :select_ir_scan
    unless state == :select_ir_scan
      tms!(1)  # => Select-DR-Scan
      update_state :select_dr_scan
      tms!(1)  # => Select-IR-Scan
      update_state :select_ir_scan
    end
    tms!(0)  # => Capture-IR
    update_state :capture_ir
    tms!(0)  # => Shift-IR
    update_state :shift_ir
    if options[:write]
      msg = "Write IR: #{options[:write]}"
    elsif options[:read]
      msg = "Read IR: #{options[:read]}"
    else
      msg = 'IR Data'
    end
    log msg, always: true do
      yield
      if options[:end_state] == :idle
        log 'Transition to Run-Test/Idle...'
      elsif options[:end_state] == :update_ir
        log 'Transition to Update-IR...'
      elsif options[:end_state] == :select_dr_scan
        log 'Transition to Select-DR-Scan...'
      end
      if @last_data_vector_shifted
        @last_data_vector_shifted = false
      else
        tms!(1)  # => Exit1-IR
        update_state :exit1_ir
      end
    end
    tms!(1)  # => Update-IR
    update_state :update_ir
    if options[:end_state] == :idle
      tms!(0)  # => Run-Test/Idle
      update_state :idle
    elsif options[:end_state] == :select_dr_scan
      tms!(1)  # => Select-DR-Scan
      update_state :select_dr_scan
    end
  else # :pause_ir
    tms!(1)  # => Exit2-IR
    update_state :exit2_ir
    tms!(0)  # => Shift-IR
    update_state :shift_ir
    yield
    log 'Transition to Pause-IR...'
    tms!(1)  # => Exit1-IR
    update_state :exit1_ir
    tms!(0)  # => Pause-IR
    update_state :pause_ir
  end
end

#state_str ⇒ Object Also known as: current_state_str

Returns the current state as a human readable string



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# File 'lib/origen_jtag/tap_controller.rb', line 323

def state_str
  STATES[state]
end

#update_state(state) ⇒ Object 



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# File 'lib/origen_jtag/tap_controller.rb', line 349

def update_state(state)
  @state = state
  log "Current state: #{state_str}" if log_state_changes
  @listeners ||= Origen.listeners_for(:on_jtag_state_change)
  @listeners.each { |l| l.on_jtag_state_change(@state) }
end