SCANSTA111 datasheet(14/29 Pages) NSC

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Level 2 Protocol (Continued)

TABLE 5. Level 2 Protocol and Op-Codes (Continued)

Instructions

Hex Op-Code

Binary Op-Code

Data Register

DGPIO

1011 0100

Dedicated GPIO Register

DGPIO

1011 0101

Dedicated GPIO Register

DGPIO

1011 0110

DedicateD GPIO Register

DGPIO

1011 0111

Dedicated GPIO Register

SGPIO

1011 1000

Shared GPIO Register

SGPIO

1011 1001

Shared GPIO Register

SGPIO

1011 1010

Shared GPIO Register

SGPIO

1011 1011

Shared GPIO Register

SGPIO

1011 1100

Shared GPIO Register

SGPIO

1011 1101

Shared GPIO Register

SGPIO

1011 1110

Shared GPIO Register

SGPIO

1011 1111

Shared GPIO Register

Other Undefined

TBD

Device Identification Register

Note 8: All other instructions act on selected STA111s only.

Note 9: Commands added to HDL version of STA111.

LEVEL 2 INSTRUCTON DESCRIPTIONS:

BYPASS: The BYPASS instruction selects the bypass reg-

ister for insertion into the active scan chain when the

’STA111 is selected.

EXTEST: The EXTEST instruction selects the boundary-

scan register for insertion into the active scan chain. The

boundary-scan register consists of seven sample only shift

cells connected to the S

(0-6) and OE inputs. On the ’STA111,

the EXTEST instruction performs the same function as the

SAMPLE/PRELOAD instruction, since there aren’t any scan-

nable outputs on the device.

SAMPLE/PRELOAD: The SAMPLE/PRELOAD instruction

selects the boundary-scan register for insertion into the ac-

tive scan chain. The boundary-scan register consists of

seven sample only shift cells connected to the S

(0-6) and OE

inputs.

IDCODE: The IDCODE instruction selects the device identi-

fication register for insertion into the active scan chain. When

IDCODE is the current active instruction the device identifi-

cation 0FC0F01F Hex is captured upon exiting the

Capture-DR state.

UNPARK: This instruction unparks the Local Scan Port Net-

work and inserts it into the active scan chain as configured

by Mode Register

0 (and Mode Register1 in the HDL) (see

Table 7). Unparked LSPs are sequenced synchronously with

the ’STA111’s TAP controller. When a LSP has been parked

in the Test-Logic-Reset or Run-Test/Idle state, it will not

become unparked until the ’STA111’s TAP Controller enters

the Run-Test/Idle state following the UNPARK instruction. An

LSP which has been parked in Test-Logic-Reset will be

parked in Run-Test/Idle upon update of an UNPARK instruc-

tion. If an LSP has been parked in one of the stable pause

states (Pause-DR or Pause-IR), it will not become unparked

until the ’STA111’s TAP Controller enters the respective

pause state. (See Figure 9, Figure 10, Figure 11, and Figure

12).

PARKTLR: This instruction causes all unparked LSPs to be

parked in the Test-Logic-Reset TAP controller state and

removes the LSP network from the active scan chain. The

LSP controllers keep the LSPs parked in the Test-Logic-

Reset state by forcing their respective TMS

n output with a

constant logic 1 while the LSP controller is in the Parked-

TLR state (see Figure 4).

PARKRTI: This instruction causes all unparked LSPs to be

parked in the Run-Test/Idle state. The update of the

PARKRTI instruction MUST immediately be followed by a

TMS

B=0 (to enter the RTI state) in order to assure stability.

When a LSP

n is active (unparked), its TMSn signals follow

TMS

B and the LSPn controller state transitions are synchro-

nized with the TAP Controller state transitions of the

’STA111. When the instruction register is updated with the

PARKRTI instruction, TMS

n will be forced to a constant logic

0, causing the unparked local TAP Controllers to be parked

in the Run-Test/Idle state. When an LSP

n is parked, it is

removed from the active scan chain.

PARKPAUSE: The PARKPAUSE instruction has dual func-

tionality. It can be used to park unparked LSPs or to unpark

parked LSPs. The instruction places all unparked LSPs in

one of the TAP Controller pause states. A local port does not

become parked until the ’STA111’s TAP Controller is se-

quenced through Exit1-DR/IR into the Update-DR/IR state.

When the ’STA111 TAP Controller is in the Exit1-DR or

Exit1-IR state and TMSB is high, the LSP controller forces a

constant logic 0 onto TMSL thereby parking the port in the

Pause-DR or Pause-IR state respectively (see Figure 4).

Another instruction can then be loaded to reconfigure the

local ports or to deselect the ’STA111 (i.e., MODESEL, GO-

TOWAIT, etc.).

If the PARKPAUSE instruction is given to a whose LSPs are

parked in Pause-IR or Pause-DR, the parked LSPs will

become unparked when the ’STA111’s TAP controller is se-

quenced into the respective Pause state.

The PARKPAUSE instruction was implemented with this

dual functionality to enable backplane testing (interconnect

testing between boards) with simultaneous Updates and

Captures.

Simultaneous Update and Capture of several boards can be

performed by parking LSPs of the different boards in the

Pause-DR TAP controller state, after shifting the data to be

updated into the boundary registers of the components on

each board. The broadcast address is used to select all

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