TABLE 1. Pin Descriptions

Pin Name

Description

No.

Pins

I/O

VCC

10

N/A

Power

GND

10

N/A

Ground

RESET

1

I

RESET Input: will force a reset of the device regardless of the current state.

ADDMASK

1

I

ADDRESS MASK input: Allows masking of lower slot input pins.

MPsel

B1/B0

1

I

MASTER PORT SELECTION: Controls selection of LSP

The unselected port becomes LSP

SB/S

1

I

Selects ScanBridge or Stitcher Mode.

LSPsel

(0-6)

7

I

In Stitcher Mode these inputs define which LSP’s are to be included in the scan chain

TRANS

1

I

Transparent Mode enable input: The value of this pin is loaded into the TRANSENABLE bit

of the control register at power-up. This value is used to control the presence of registers

and pad-bits in the scan chain while in the stitcher mode.

TLR_TRST

1

I

Sets the driven value of TRST

reset. During RESET = "0" or TRST

tied low to match the function of the SCANSTA111

TLR_TRST

6

1

I

This pin affects TRST of LSP

SCANSTA111

TDI

2

I

BACKPLANE TEST DATA INPUT: All backplane scan data is supplied to the ’STA112

through this input pin. MPsel

which is LSP

Ω internal pull-up resistor and no ESD clamp diode

(ESD is controlled with an alternate method). When the device is power-off (V

this input appears to be a capacitive load to ground (Note 1). When V

floating but tied to V

TMS

2

I/O

BACKPLANE TEST MODE SELECT: Controls sequencing through the TAP Controller of the

’STA112. Also controls sequencing of the TAPs which are on the local scan chains.

MPsel

bidirectional TRI-STATE pin has 24mA of drive current, with a 25K

Ω internal pull-up resistor

and no ESD clamp diode (ESD is controlled with an alternate method). When the device is

power-off (V

V

pull-up to ground.

TDO

2

I/O

BACKPLANE TEST DATA OUTPUT: This output drives test data from the ’STA112 and the

local TAPs, back toward the scan master controller. This bidirectional TRI-STATE pin has

12mA of drive current. MPsel

which is LSP

power-off (V

TCK

2

I/O

TEST CLOCK INPUT FROM THE BACKPLANE: This is the master clock signal that controls

all scan operations of the ’STA112 and of the local scan ports. MPsel

port is the master backplane port and which is LSP

have 24mA of drive current with hysterisis. This input has no pull-up resistor and no ESD

clamp diode (ESD is controlled with an alternate method). When the device is power-off (V

DD

floating), this input appears to be a capacitive load to ground (Note 1). When V

not floating but tied to V

TRST

2

I/O

TEST RESET: An asynchronous reset signal (active low) which initializes the ’STA112 logic.

MPsel

bidirectional TRI-STATE pin has 24mA of drive current, with a 25K

Ω internal pull-up resistor

and no ESD clamp diode (ESD is controlled with an alternate method). When the device is

power-off (V

V

pull-up to ground.

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