Quicklogic Corporation

International Business Machines Corporation

Chihhung Liao

Ket Chong Yap

Shieh Huan Yen

Derick Gardner Behrends

George Francis Paulik

Salvatore Nicholas Storino

Peder James Paulson

Ryan Charles Kivimagi

Brian Joy Reed

Phu Nguyen

Vimal Ramannhai Patel

A programmable logic device (PLD) supports scan testing of configurable logical blocks using scannable word line (WL) shift register (WLSR) chains to enable writes to configurable memory bits while scan test data is input via a scan chain comprising scannable bit line (BL) shift registers (BLSRs). Input test data may be shifted onto BLs to write data into a configurable memory bit when a corresponding WL associated with the configurable memory bit is asserted. Logic blocks may comprise: latch-based configurable memory bits, scannable WLSRs forming a distinct WLSR chain in shift mode and driving corresponding WLs. Each WL, when asserted, enables writes to a corresponding configurable memory bit. A scannable BLSR receives serial scan test vector input in shift mode and drives a corresponding BL coupled to the configurable memory bit to write data to the configurable memory bit when the associated WL is asserted.

Programmable logic device with design for test functionality

An area efficient readable and resettable configuration memory latch maintains latch data integrity through read and write operations and includes a non-terminated inout bit line (BL). During write operations, enabled by a Word Line Write (WLW) signal, the non-terminated inout BL drives data to be written, while, during read operations, enabled by a Word Line Read (WLR) signal, the state of the BL is indicative of a data stored in the latch. A pull-down network is activated when the WLR signal is asserted and the stored data is logic one and, when activated, operates to pull down the BL to logic zero; the pull-down network is inactive otherwise. A weak pull-up operates to pull up the BL when the pull-down network is inactive. A sensing block is configured to sense the state of the BL when the WLR signal and a read enable signal are both asserted.

Configuration latch for programmable logic device

An area efficient input terminated readable and resettable configuration memory latch is disclosed. A pull-up network and a pair of pull-down networks operate to set the value of an internal node based, in part, on the state of the input terminated bit line and a word line write input. The internal node is inverted to form the output of the configuration memory latch. A reset line operates to reset the latch and a reset cycle is initiated prior to each write cycle. In some embodiments, the configuration memory latch includes a scan mode input, which, when asserted, facilitates automated testing of a programmable logic device that includes the configuration memory latch. Asserting the scan mode input enables Design for Test functionality. A sensing block is configured to sense the state of the bit when a word line read signal and a read enable signal are both asserted.

Area-efficient configuration latch for programmable logic device

An area efficient readable and resettable configuration memory latch is disclosed that maintains latch data integrity through read and write operations and includes a non-terminated inout bit line (BL). During write operations, enabled by a Word Line Write (WLW) signal, the non-terminated inout BL drives data to be written, while, during read operations, enabled by a Word Line Read (WLR) signal, the state of the BL is indicative of a data stored in the latch. A pull-down network is activated when the WLR signal is asserted and the stored data is logic one and, when activated, operates to pull down the BL to logic zero; the pull-down network is inactive otherwise. A weak pull-up operates to pull up the BL when the pull-down network is inactive. A sensing block is configured to sense the state of the BL when the WLR signal and a read enable signal are both asserted.

A bit line (BL) may be coupled at a first end to a BL driver (BLD) and at a second end to a BL receiver (BLR). The BL include a plurality of sections and each BL section may be coupled to at least one corresponding sectional configuration memory latch controlled by: at least one sectional word line write (WLW-k) signal, which when asserted enables data to be written into the at least one corresponding sectional configuration memory latch when a corresponding tri-stateable sectional driver (SD-k) is activated, and at least one sectional word line read (WLR-k) signal, which when asserted enables data to be from the at least one corresponding sectional configuration memory latch when the corresponding sectional pull-up (PU-k) is activated.

Sectional configuration for programmable logic devices

An eFuse circuit may include a wordline, a first eFuse, a first logic gate, a first blowFET, and a first bitline discharge device. The first eFuse may have a first end coupled to the wordline and a second end. The first eFuse may have a first resistance when unblown and a second resistance when blown. The first logic gate may be coupled to the first end of the first eFuse. The first logic gate may be capable of driving enough current to blow the first eFuse. The first blowFET may have a source coupled to a first supply voltage, a gate coupled to a program signal, and a drain coupled to the second end of the first eFuse. The first bitline discharge device may have a gate coupled to the second end of the first eFuse, a source coupled to the first supply voltage, and a drain coupled to a first bitline.

State sensing system for eFuse memory

An apparatus and method provide logically controlled masking of one or more maskable data bits from a plurality of data bits that are input to a dynamic logic circuit. No masking logic and attendant delay penalty is coupled in the data path that is not needed for unmasked bits from the plurality of data bits that do not need masking. A system clock has a precharge phase and an evaluate phase. A first clock buffer is coupled to a precharge switch and precharges a dynamic node during the precharge phase. A second clock buffer having substantially the same delay from system clock input to an output of the second clock buffer is gated by a derivative of a mask. The output of the second clock buffer controls one or more switches in series with switches controlled by the maskable data bits.

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Fremont, CA, United States of America

Chihhung Liao