Patent ID: 6201404
Filing Date: 2001-03-13
Classification: H03K

Abstract:
A programmable logic device in which redundant logic is switched into use in place of defective logic to repair the device, the programmable logic device being programmed by programming data that is loaded into the programmable logic device via a data input on the device, the programmable logic device comprising:a plurality of rows and columns of programmable logic regions, wherein one of the rows of programmable logic regions is a row of redundant programmable logic regions;a plurality of vertical conductors associated with each of the columns of programmable logic regions;a plurality of horizontal conductors associated with each of the rows of programmable logic regions;a plurality of data registers, each associated with a different row and each having a serial data input, a serial data output, and a plurality of parallel data outputs; andswitching circuitry that receives the programming data from the data input and that is connected to the serial data inputs and the serial data outputs, wherein the switching circuitry normally serially loads the programming data into the data registers by connecting the data registers in a chain in which the serial data output of each data register is connected to the serial data input of the data register in the next row, and wherein when a defect is detected in one of the rows, the switching circuitry is configured to serially load the programming data into the data registers by connecting the data registers in a chain that bypasses the defective row.