pc87591l-n05 National Semiconductor Corporation, pc87591l-n05 Datasheet - Page 226

• Manufacturer Part Number: pc87591l-n05
• Description: Lpc Mobile Embedded Controller
• Manufacturer: National Semiconductor Corporation

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4.0 Embedded Controller Modules
For a detailed description of the controller states, see the IEEE 1149.1b-1994 specifications.
All state transitions of the TAP controller occur based on the value of TMS on the rising edge of TCK. TAP actions (described
in Sections 2.1.3 to 2.1.7) occur either on the rising or falling edge of TCK in each controller state, as shown in Figure 79.
TAP Controller Operation
The TAP controller changes state only in response to the following events:
The TAP controller generates signals to control the operation of the TAP registers and associated PC87591L-N05 reset, ISE
interrupt control and data link circuitry.
The TDO output buffer and the circuitry that selects the register output fed to TDO are controlled as shown in Table 27.
Changes at TDO, as defined in Table 27, occur on the falling edge of TCK after entry into the state.
TAP Controller Initialization
Circuitry built into the PC87591L-N05 forces the TAP controller into TAP-Reset state at power-up in an asynchronous man-
ner.
The TAP controller must not be initialized by operation of any system input, such as a system reset.
• A rising edge of TCK
• Power-up
Controller State
Controller State
Select-DR-Scan
Select-IR-Scan
Run-Test-Idle
Capture-DR
Update-DR
Capture-IR
TCK
Tap-Reset
Update-IR
Pause-DR
Pause-IR
Exit2-DR
Shift-DR
Exit1-IR
Exit2-IR
Exit-DR
Shift-IR
State Entered
Figure 79. Timing of Actions in a Controller State
Table 27. TAP Operation in Each Controller State
Actions Occurring on the
Register Selected to Drive TDO
Falling Edge of TCK
(Continued)
Undefined
Undefined
Undefined
Undefined
Undefined
Instruction
Undefined
Undefined
Undefined
Undefined
Undefined
Undefined
Undefined
Undefined
Undefined
Test Data
226
Actions Occurring on
Rising Edge of TCK
TDO Driver Level
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Inactive
Active
Active
Revision 1.2