Specifications ispLSI 2128VL

9

Signal Descriptions

RESET

Active Low (0) Reset pin resets all the registers in the device.

GOE 0, GOE1

Global Output Enable input pins.

Y0, Y1, Y2

Dedicated Clock Input – These clock inputs are connected to one of the clock inputs of all the GLBs in

the device.

BSCAN

Input – Dedicated in-system programming Boundary Scan enable input pin. This pin is brought low to

enable the programming mode. The TMS, TDI, TDO and TCK controls become active.

TDI/IN 0

Input – This pin performs two functions. When

BSCAN is logic low, it functions as a serial data input pin

to load programming data into the device. When

BSCAN is high, it functions as a dedicated input pin.

TCK/IN 3

Input – This pin performs two functions. When

BSCAN is logic low, it functions as a clock pin for the

Boundary Scan state machine. When

BSCAN is high, it functions as a dedicated input pin.

TMS/IN 1

Input – This pin performs two functions. When

BSCAN is logic low, it functions as a mode control pin for

the Boundary Scan state machine. When

BSCAN is high, it functions as a dedicated input pin.

TDO/IN 2

Output/Input – This pin performs two functions. When

BSCAN is logic low, it functions as an output pin

to read serial shift register data. When

BSCAN is high, it functions as a dedicated input pin.

IN 4 - IN 7

Dedicated Input Pins to the device.

GND

Ground (GND)

VCC

Vcc

No Connect

I/O

Input/Output Pins – These are the general purpose I/O pins used by the logic array.

Signal Name

Description

1. NC pins are not to be connected to any active signals, VCC or GND.