Abstract: An embodiment of a technique to determine an expected occurrence of a signal is disclosed. The technique includes receiving first and second signals, and storing delay information representing an expected time delay from an occurrence of the first signal to a point in time corresponding approximately to an expected occurrence of the second signal. The technique further includes responding to an occurrence of the first signal by: waiting for a time interval equivalent to the expected time delay, evaluating the second signal at approximately the end of the time interval, and adjusting the stored delay information if the second signal occurred outside a time window associated with the end of the time interval.

Abstract: An embodiment of a technique to capture and locally synchronize data is disclosed. The technique includes receiving first and second signals through a first interface, and receiving a third signal through a second interface where the third signal is unsynchronized with respect to the second signal. The technique further includes detecting a first phase difference between the second and third signals, and generating a fourth signal in a manner so that a second phase difference between the fourth signal and one of the second or third signals is a function of the first phase difference. In addition, the technique includes storing a state of the first signal in response to the fourth signal, and thereafter supplying the stored state of the first signal to the second interface.

Abstract: A technique is provided that involves: configuring a clock generation circuit to output a first signal having a first frequency that is one of a plurality of frequencies that are different; generating in a clock section of a further circuit as a function of the first signal a second signal having a second frequency that is one of the plurality of frequencies other than the first frequency; and configuring the clock section to supply to the further circuit a clock signal that is one of the first and second signals.

Abstract: An embodiment of a technique to transfer data includes: operating a memory interface using memory access cycles that each include T successive time slots each provided for transfer of B bits of data, where T and B are positive integers; selecting one of first or second predetermined integers as one of T or B; and transferring a quantity of data Q between the memory interface and another interface. The transferring includes: automatically determining a value of M memory access cycles as a function of the one of T or B; causing a data transfer sequence on the memory interface that includes M successive memory access cycles and thus M·T time slots; automatically determining a subset of the M·T time slots as a function of the one of T or B; and transferring the quantity of data Q through the memory interface during the subset of time slots.

Abstract: An embodiment of a technique to transfer data between two different interfaces is disclosed. The embodiment of the technique includes: manipulating data arriving at a first data interface with a first word width into data with a second word width; transferring the manipulated data to a second data interface having the second word width; and selecting one of a plurality of different word widths for one of the first or second word widths.

Abstract: Some embodiments involve a circuit having first and second interfaces, and configurable structure to identify a selected integer number that is one of a plurality of different integer numbers associated with respective different configurations. In one embodiment, a conversion section organizes lines of the second interface into line groups equal in number to the selected integer number, and carries out a conversion operation in which it supplies to each line group a respective incoming data segment received through the first interface. In another embodiment, a conversion section organizes the lines of the first interface into line groups equal in number to the selected integer number, and carries out a conversion operation in which it supplies to the second interface a respective incoming data segment from each line group.

Abstract: A technique is provided for memory control in a device having programmable circuitry, including providing a dedicated memory controller circuit in the device before the programmable circuitry is field programmed. Another technique involves fabricating a device, where the fabricating involves forming programmable circuitry that includes a dedicated memory controller circuit before the circuitry is field programmed.

Abstract: A device has first circuitry and also second circuitry that includes an interface and command ports that can each receive commands from the first circuitry, each command requesting an information transfer through the interface. A technique relating to the device involves dynamically enabling and disabling at least one of the command ports under control of the first circuitry, and using a priority list specifying an order of priority for a group of the command ports to identify and cause a command to be accepted from the command port of highest priority that contains a command and is currently enabled.

Abstract: An apparatus includes a programmable device that has an interface and command ports that can each receive commands, each command requesting an information transfer through the interface. A technique relating to the device involves: selecting during field programming a number of priority definitions; configuring each of the priority definitions during field programming to specify an order of priority for a group of the command ports; and using the priority definitions in succession and, for each of the priority definitions, causing a command to be accepted from the command port of highest priority that contains a command.

Abstract: A method of calibrating memory controller signals within an integrated circuit (IC) can include determining an internal delay of a clock network of the IC and generating a calibrated clock signal by applying a first delay to an uncalibrated clock signal, wherein the first delay is determined by subtracting the internal delay of the clock network of the IC from a bitperiod of the uncalibrated clock signal. The method can include determining a classification of at least one data signal according to timing of positive and negative edges of the at least one data signal in comparison with edges of the calibrated clock signal and aligning at least one of positive or negative edges of the at least one data signal to occur at midpoints between edges of the calibrated clock signal according to the classification of the at least one data signal.

Abstract: Within an integrated circuit comprising a memory controller, a method can include, responsive to determining that the memory controller is performing a refresh operation, calculating a new tap setting according to a new maximum value and an old tap setting of the delay circuit. The new maximum value specifies a number of taps of the delay circuit that approximates a predetermined time span. The method can include dynamically adjusting a delay applied to a signal by a delay circuit according to the new tap setting. The delay circuit generates a delayed signal that is provided to the memory controller.

Abstract: A multiplier-accumulator includes a pre-adder, a multiplier, an accumulator, multiplexing logic, and control logic. The pre-adder is configured to sum a first input and a second input to produce a pre-sum output. The multiplier is configured to multiply a third input and the pre-sum output to produce a product output. The accumulator is configured to sum a pair of accumulator inputs to produce a sum output. The multiplexer is configured to select the pair of accumulator inputs from a plurality of multiplexer inputs, where the plurality of multiplexer inputs includes the product output and the sum output. The control logic is configured to control operation of the pre-adder, the accumulator, and the multiplexer logic. In an example, each of the first input, the second input, the third input, and the sum output is coupled to programmable interconnect of a programmable logic device.

Abstract: A technique is applicable to a device having programmable circuitry that includes a first interface having a plurality of first address terminals, a second interface having a plurality of second address terminals, and a configurable interconnect structure coupled between the first and second interfaces. The technique includes configuring the interconnect structure during field programming to electrically couple each of the address terminals in a first subset of the first address terminals to respective address terminals in a second subset of the second address terminals according to a selected one of a plurality of different mapping functions.

Abstract: A method of testing input signals coupled to a circuit for performing a predetermined function is disclosed. The method comprises coupling input signals to inputs of the circuit by way of programmable interconnects; controlling the paths of the input signals within the circuit from the inputs to an output of the circuit; maintaining the states of the input signals coupled to the inputs of the circuit and routed to the output of the circuit; and testing output signals of the circuit to determine whether the correct input signals were provided to the inputs of the circuit by way of the programmable interconnects. A device having programmable logic which enables testing of input signals is also disclosed.

Abstract: An integrated circuit system (120) includes a memory array (122) storing a configuration data set to configure an integrated circuit. The integrated circuit (121) includes a configuration memory (128) and a configuration controller state machine (126). The configuration controller state machine operates so as to read a read-check signature at a read-check address of the memory array (122) and to compare the read-check signature with a standard signature stored in the integrated circuit (121). If the read-check signature passes the comparison, the configuration controller state machine (126) loads the configuration data set from the memory array to the configuration memory (128) of the integrated circuit.

Abstract: A method and apparatus involve operating a circuit that includes a first portion and a second portion, including: operating the first portion in synchronism with a clock signal; maintaining in the first portion a logical value that can vary dynamically; and operating the second portion in a selected one of first and second operational modes. The operating of the second portion includes: responding to the occurrence of a control signal during operation in the first operational mode by causing the second portion to force the logical value in the first portion to a predetermined logical state in a manner asynchronous to the clock signal; and responding to the occurrence of the control signal during operation in the second operational mode by causing the second portion to force the logical value in the first portion to the predetermined logical state in a manner synchronized with the clock signal.

Abstract: System and apparatus for data validation is described. An initialization controller includes an initialization state machine. The initialization state machine is configured to cause configuration data to be transferred from memory internal or external to the integrated circuit to other memory internal to the integrated circuit. The configuration data is stored in the integrated circuit, read back from storage in the integrated circuit, and compressed by the integrated circuit after being read back. The configuration data is compressed into a signature, which may be compared with an expected result for the signature.

Abstract: Structures and methods for transferring data from non-volatile to volatile memories. An extra bit, called a “transfer bit”, is included in each data word. The transfer bit is set to the programmed value, and is monitored by a control circuit during the memory transfer. If the supply voltage is sufficient for correct programming, the transfer bit is read as “programmed”, and the data transfer continues. If the supply voltage is below the minimum supply voltage for proper programming, the transfer bit is read as “erased”, and the data transfer is reinitiated. In one embodiment, a second transfer bit set to the “erased” value is included in each word.

Abstract: Described are small, efficient SRAM cells that are insensitive to read errors. SRAM cells in accordance with one embodiment include a pair of cross-coupled inverters extending between first and second bit nodes and a read amplifier extending from one of the first and second bit nodes to an associated bitline. During a read access to a given memory cell, the corresponding read amplifier isolates the bit nodes from the bitlines to prevent the voltage on bitline BL from disturbing data stored in the memory cell.

Abstract: Described are programmable logic devices with configuration memory cells that function both as RAM and ROM. A PLD incorporating these memory cells to store configuration data can be mask-programmed with a customer design, rendering the PLD an application-specific integrated circuit (ASIC). The mask programming can be selectively disabled, in which case each configuration memory cell behaves as a static, random-access memory (SRAM) bit. In this mode, a PLD employing these dual-mode memory cells behaves as a reprogrammable PLD, and can therefore be tested using generic test procedures developed for the PLD. The dual-mode memory cells thus eliminate the burdensome task of developing application-specific test procedures for designs ported from a PLD. As an added benefit, in the ROM mode these memory cells are not susceptible to radiation-induced upsets, so for example, PLDs incorporating these memory cells are better suited for aerospace applications than conventional SRAM-based PLDs.