Lattice Semiconductor Corporation

Jeffrey S Byrne

Howard H Tang

Jack Tim Wong

Clark Wilkinson

Daniel B Young

In accordance with an embodiment of the present invention, a programmable logic device (PLD, such as a field programmable gate array (FPGA)) includes a plurality of input/output blocks adapted to precondition registers within the programmable logic device with desired signal values prior to release of control of the input/output blocks to user-defined logic provided by a reconfiguration.

Transparent field reconfiguration for programmable logic devices

In accordance with an embodiment of the present invention, a programmable logic device (PLD, such as a field programmable gate array (FPGA)) includes a plurality of input/output blocks having boundary scan cells that are adapted to precondition registers within a logic area of the programmable logic device with desired signal values prior to release of control of the input/output blocks to user-defined logic provided by a reconfiguration.

A device includes data input and data output pins such as found in a JTAG port and a first plurality of boundary scan cells. The device is configurable to support a secondary boundary scan cells formed from the first plurality of boundary scan cells and a second plurality of boundary scan cells in at least one external device. In one embodiment, the device includes a demultiplexer which may be configured to support a primary boundary scan chain between the JTAG port and the first plurality of boundary scan cells. The demultiplexer may also be configured to support the secondary boundary scan chain between the JTAG port and the first and the second plurality of boundary scan cells.

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Portland, OR, United States of America

Jeffrey S Byrne