Xilinx, Inc.

Subodh Kumar

Uma E Durairajan

Weiguang Lu

Michelle Zeng

Hsiao H Chen

James M Simkins

Matthew H Klein

James E Ogden

David P Schultz

Sridhar Subramanian

Vasisht Mantra Vadi

Santosh Yachareni

Amitava Majumdar

Alvin Y Ching

Sridhar Narayanan

Ian L McEwen

Kumar Rahul

Adam Elkins

Thomas H Strader

Karthy Rajasekharan

Jaime D Lujan

Philip R Haratsaris

Aniruddha Talukder

Kameswari Sb Angada

Richard D Freeman

Ghazaleh Mirjafari

Eric M Schwarz

Embodiments herein describe a reconfigurable integrated circuit (IC) where data can be retained in memory when performing a partial reconfiguration. Partial reconfiguration includes reconfiguring programmable logic in the IC while certain functions of the IC remain operational or active. In one embodiment, the reconfigurable IC includes control logic for saving or retaining data in the IC during a partial reconfiguration. That is, rather than clearing the memory elements, the user can specify that the memory blocks containing certain data should be retained while the other memory blocks can be cleared. In this manner, the data can be retained in the IC during a partial reconfiguration which saves time, power, and cost. Once partial reconfiguration is complete, the newly configured programmable logic can retrieve and process the saved data from the on-chip memory.

Retaining memory during partial reconfiguration

Methods and apparatus are described for converting a pre-silicon Open Verification Methodology or Universal Verification Methodology (OVM/UVM) device under test (DUT) into a design implementable on a programmable integrated circuit (IC) and for converting the pre-silicon OVM/UVM stimulus from the driver and expected response from the scoreboard into timing aware stimulus-response vectors that can be applied through the tester onto the pads of the programmable IC that contains the implemented design. This approach can handle the clock and other input stimuli changing concurrently in the pre-silicon testbench, and the vectors generated therefrom will be in the proper form so as to work deterministically on the silicon on the tester.

Method to convert OVM/UVM-based pre-silicon tests to run post-silicon on a tester

In an example, a memory circuit in a programmable integrated circuit (IC) includes: a control port and a clock port; a configurable random access memory (RAM) having a control input and a clock input; input multiplexer logic coupled to the control input and the clock input; and a state machine coupled to the input multiplexer logic and configuration logic of the programmable IC, the state machine configured to: in response to being enabled by the configuration logic, control the input multiplexer logic to switch a connection of the control input from the control port to the state machine and, subsequently, switch a connection of the clock input from the clock port to a configuration clock source; and in response to being disabled by the configuration logic, control the input multiplexer logic to switch the connection of the clock input from the configuration clock source to the clock port and, subsequently, switch the connection of the control input from the state machine to the control port.

Implementing robust readback capture in a programmable integrated circuit

Methods and apparatus are described for providing and operating an efficient infrastructure to implement a built-in clock stop and scan dump (CSSD) scheme for fabric blocks, such as block random access memory (BRAM), UltraRAM (URAM), digital signal processing (DSP) blocks, configurable logic elements (CLEs), and the like. This is a very useful feature for system debug and can also be applied for emulation use cases (e.g., FPGA emulation). This scheme can be applied to any tiled architecture that has highly repetitive blocks. The infrastructure may include a DFx controller shared across multiple tiled blocks with some distributed logic in each block, in an effort to minimize or at least reduce area overhead. The infrastructure may also minimize or at least reduce utilization of fabric resources in an effort to ensure the least perturbation of the original design, such that the design issues being debugged can be easily reproduced.

Efficient system debug infrastructure for tiled architecture

Circuits and methods for initializing a memory. Each row of the memory includes data bits and associated parity bits. A write buffer contains bit values for initializing the memory, and a control circuit performs a first set of write operations that write values from the write buffer to the data bits of the memory without writing values to the associated parity bits. The write buffer performs a second set of write operations that write values from the write buffer to the parity bits associated with the data bits without writing data to the data bits.

Memory initialization

An embodiment of a memory module is disclosed. This memory module is a configurable hard macro. A portion of this memory module includes a data input multiplexer coupled to select between cascaded data and direct/bused data. Such portion further includes, a memory coupled to receive output from the data input multiplexer for storage therein, and a register input multiplexer coupled to select between read data from the memory and the cascaded data. This memory module further includes: a register coupled to receive output from the register input multiplexer, a latch/register mode multiplexer coupled to select between the read data from the memory and registered data from the register, and a data output multiplexer coupled to select between the cascaded data and output from the latch/register mode multiplexer to provide output data.

Configurable embedded memory system

An apparatus relates generally to a clock generator is disclosed. The clock generator is coupled to receive an input clock signal and further coupled to provide an output clock signal. An address and control register is coupled to receive an address signal and the output clock signal. An access generator is coupled to receive the output clock signal. The clock generator includes: an input node coupled to receive the input clock signal; at least one pulse generator coupled to the input node to receive the input clock signal and further coupled to provide a clock control signal; and a control gate coupled to the input node to receive the input signal and further coupled to the at least one pulse generator to receive the clock control signal. The clock control signal is provided in a non-toggling state for a high-frequency mode and in a toggling state for a low-frequency mode.

Bimodal clock generator

An integrated circuit and method for using a synchronous reset pulse to reset a circuitry comprising a plurality of clock domains are disclosed. For example, the method of the present disclosure provides a reset signal that is synched to one clock, takes the synchronous signal and resets circuits in a plurality of clock domains. In order to reset a portion of the circuit which is in a particular clock domain, the reset needs to be synchronized to the clock of the particular domain.

Method and apparatus for using a synchronous reset pulse to reset circuitry in multiple clock domains

A circuit can include address evaluation circuitry coupled to an address bus of a memory and configured to generate a first control signal responsive to determining that an address on the address bus has not changed for a current clock cycle from a previous clock cycle. The circuit can include write enable evaluation circuitry coupled to the memory and configured to generate a second control signal responsive to determining that a write enable signal of the memory is de-asserted for the current clock cycle and for the previous clock cycle. The circuit can include clock enable circuitry coupled to a clock enable port of the memory and configured to generate a clock enable signal to the clock enable port of the memory responsive to the first control signal and the second control signal.

Reducing dynamic power consumption of a memory circuit

A data value is read from one port of a dual-port memory cell during a clock cycle. A WRITE assist pulse having a delay from an end-of-read signal is generated. The delay and duration of the WRITE assist pulse are optionally user-selectable. A high voltage (e.g., Vdd) is coupled to the bitlines (e.g., BL-A, BLc-A) of the first port during the WRITE assist pulse, and a low voltage value (e.g., zero) is written to the memory cell through the second port (e.g., BL-B, BLc-B) during the clock cycle.

Dual port memory with write assist

A computer-implemented method of identifying timing paths of a circuit block can include representing a circuit block including at least one bypassable component as a block diagram having a plurality of elements linked by nodes. The method can include generating a map file including a text description of each element within the block diagram, wherein the text description of each element specifies a bypass indicator for the element. The method also can include generating a plurality of sub-paths from the map file, determining timing paths from the plurality of sub-paths by selectively combining different ones of the plurality of sub-paths according to commonality of starting points and ending points of the plurality of sub-paths, and outputting the timing paths.

Determining timing paths within a circuit block of a programmable integrated circuit

A circuit for repairing defective memory of an integrated circuit is disclosed. The circuit includes blocks of memory; and interconnect elements providing data to each of the blocks of memory, where the interconnect elements enable coupling together the signals for programming the blocks of memory. The circuit also includes a directory of locations for defective memory cells of blocks of memory, where the directory of locations is common to the blocks of memory for storing locations of defective memory cells of the blocks of memory. Methods of repairing defective memory of an integrated circuit are also disclosed.

Growing community of inventors

San Jose, CA, United States of America

Subodh Kumar