Abstract: In one embodiment, a programmable logic device includes configuration memory, an SPI port for receiving a bitstream, a chip select output pin, and configuration control circuitry. The chip select output pin can provide a chip select signal having a first logic state for selecting another device (such as another PLD) to receive a bitstream and a second logic state for de-selecting the other device. The configuration control circuitry is responsive to a command embedded in the received bitstream to drive the chip select output pin from the second logic state to the first logic state, thereby selecting the other device to receive the bitstream. Several such PLDs connected in a daisy chain can thus be configured from a single configuration source or have their configuration data read back while so connected.

Abstract: In one embodiment, a method of verifying a programming operation of a programmable logic device includes storing in non-volatile memory within the programmable logic device configuration data and a pre-calculated code value based on the configuration data. The method further includes transferring the configuration data from non-volatile memory to configuration memory within the programmable logic device; calculating a code value based on the configuration data transferred from the non-volatile memory to the configuration memory; and comparing the calculated code value to the pre-calculated code value.

Abstract: Various techniques are described to provide an internally triggered reconfiguration of a programmable logic device (PLD). In one example, a PLD includes configuration memory adapted to store first configuration data to configure the PLD for its intended function. The PLD also includes a bus interface adapted to interface with configuration data storage memory. The PLD further includes user logic configured by the first configuration data and adapted to provide a reconfiguration signal to trigger a reconfiguration of the PLD. In addition, the PLD includes a bus interface controller responsive to the reconfiguration signal for loading second configuration data from the configuration data storage memory via the bus interface.

Abstract: In one embodiment of the invention, a programmable logic device includes configuration memory and a controller. The controller can read a first bitstream from a first memory block of non-volatile memory and detect whether the first bitstream contains a valid preamble as the first bitstream is read from the non-volatile memory and before configuration data in the first bitstream is programmed into the volatile configuration memory. If a valid preamble is detected in the first bitstream, the controller programs the configuration memory with configuration data in the first bitstream. If a valid preamble is not detected in the first bitstream, the controller reads a second bitstream from a second memory block of the non-volatile memory.

Abstract: Systems and methods provide register data retention techniques for a programmable logic device in accordance with one or more embodiments of the present invention. For example, in one embodiment, a programmable logic device includes a plurality of logic blocks adapted to generate user data during operation of the programmable logic device; a plurality of registers adapted to store the user data during a reprogramming operation of the programmable logic device; and configurable routing resources adapted to provide a programmed data path between the logic blocks and the registers.

Abstract: In one embodiment, a programmable logic device (PLD) includes a slave port and a master port. The slave port can receive a configuration data bitstream and a slave clock signal from a master port of a first external device. The master port can provide the configuration data bitstream and a master clock signal from the PLD to a slave port of a second external device. An interface block in the PLD can pass the configuration data bitstream from the slave port through the PLD to the master port. In another embodiment, a PLD includes a slave serial peripheral interface (SPI) port and configuration memory. The slave SPI port can receive a configuration data bitstream and a slave clock signal from a master SPI port of an external device. The configuration memory stores the received bitstream for configuring the PLD.

Abstract: In accordance with an embodiment of the present invention, a programmable logic device includes configuration memory to store configuration data to configure the programmable logic device, and a non-volatile memory to store configuration data for transfer to the configuration memory to configure the programmable logic device. The non-volatile memory also stores a first code value based on the configuration data stored in the non-volatile memory. A code block calculates a second code value based on the configuration data transferred to the configuration memory. A comparator compares the first code value to the second code value to verify that the configuration data was not corrupted during the transfer from the non-volatile memory to the configuration memory.

Abstract: Various techniques are disclosed herein to provide an improved approach to the loading of configuration data into configuration memory of programmable logic devices. For example, in accordance with one embodiment of the present invention a method of configuring a programmable logic device includes reading a first bitstream from a first memory block of an external memory device. The first bitstream is checked for errors and a second bitstream is read from a second memory block of the external memory device if an error is detected. Configuration memory of the programmable logic device is programmed with configuration data provided in one of the first bitstream and the second bitstream.

Abstract: Systems and methods are disclosed herein to provide an improved approach to the configuration of integrated circuits such as programmable logic devices (PLDs). In one example, a method of operating a PLD includes receiving a configuration data bitstream at a slave serial peripheral interface (SPI) port of a PLD from a master SPI port of a first external device. The method also includes passing the configuration data bitstream through the PLD from the slave SPI port of the PLD to a master SPI port of the PLD. The method further includes providing the configuration data bitstream from the master SPI port of the PLD to a slave SPI port of a second external device.

Abstract: Systems and methods provide register data retention techniques for a programmable logic device in accordance with one or more embodiments of the present invention. For example, in accordance with an embodiment, a method includes programming routing resources between programmable logic and registers of a programmable logic device to provide a data path for data prior to a reprogramming; transferring data from the programmable logic, prior to the reprogramming, to the registers via the data path to store the data within the programmable logic device during the reprogramming; reprogramming the programmable logic device, wherein the reprogramming provides a reprogrammed data path between the programmable logic and the registers of the programmable logic device; and transferring the data within the programmable logic device from the registers via the reprogrammed data path for use by the programmable logic after the reprogramming of the programmable logic device has been completed.