DS3181/DS3182/DS3183/DS3184
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Shift-DR. The Test Data Register selected by the current instruction is connected between JTDI and JTDO and
shifts data one stage toward its serial output on each rising edge of JTCLK. If a Test Register selected by the
current instruction is not placed in the serial path, it maintains its previous state.
Exit1-DR. While in this state, a rising edge on JTCLK with JTMS high puts the controller in the Update-DR state
that terminates the scanning process. A rising edge on JTCLK with JTMS low puts the controller in the Pause-DR
state.
Pause-DR. Shifting of the Test registers is halted while in this state. All Test registers selected by the current
instruction retain their previous state. The controller remains in this state while JTMS is low. A rising edge on
JTCLK with JTMS high puts the controller in the Exit2-DR state.
Exit2-DR. While in this state, a rising edge on JTCLK with JTMS high puts the controller in the Update-DR state
and terminate the scanning process. A rising edge on JTCLK with JTMS low puts the controller in the Shift-DR
state.
Update-DR. A falling edge on JTCLK while in the Update-DR state latches the data from the shift register path of
the Test registers into the data output latches. This prevents changes at the parallel output due to changes in the
shift register. A rising edge on JTCLK with JTMS low, puts the controller in the Run-Test-Idle state. With JTMS
high, the controller enters the Select-DR-Scan state.
Select-IR-Scan. All Test registers retain their previous state. The Instruction register remains unchanged during
this state. With JTMS low, a rising edge on JTCLK moves the controller into the Capture-IR state and initiates a
scan sequence for the Instruction register. JTMS high during a rising edge on JTCLK puts the controller back into
the Test-Logic-Reset state.
Capture-IR. The Capture-IR state is used to load the shift register in the Instruction register with a fixed value of
001. This value is loaded on the rising edge of JTCLK. If JTMS is high on the rising edge of JTCLK, the controller
enters the Exit1-IR state. If JTMS is low on the rising edge of JTCLK, the controller enters the Shift-IR state.
Shift-IR. In this state, the shift register in the Instruction register is connected between JTDI and JTDO and shifts
data one stage for every rising edge of JTCLK toward the serial output. The parallel registers, as well as all Test
registers, remain at their previous states. A rising edge on JTCLK with JTMS high moves the controller to the Exit1-
IR state. A rising edge on JTCLK with JTMS low keeps the controller in the Shift-IR state while moving data one
stage through the Instruction shift register.
Exit1-IR. A rising edge on JTCLK with JTMS low puts the controller in the Pause-IR state. If JTMS is high on the
rising edge of JTCLK, the controller enters the Update-IR state and terminate the scanning process.
Pause-IR. Shifting of the Instruction register is halted temporarily. With JTMS high, a rising edge on JTCLK puts
the controller in the Exit2-IR state. The controller remains in the Pause-IR state if JTMS is low during a rising edge
on JTCLK.
Exit2-IR. A rising edge on JTCLK with JTMS high put the controller in the Update-IR state. The controller loops
back to the Shift-IR state if JTMS is low during a rising edge of JTCLK in this state.
Update-IR. The instruction shifted into the Instruction shift register is latched into the parallel output on the falling
edge of JTCLK as the controller enters this state. Once latched, this instruction becomes the current instruction. A
rising edge on JTCLK with JTMS low, puts the controller in the Run-Test-Idle state. With JTMS high, the controller
enters the Select-DR-Scan state.