Abstract: Overvoltage protection circuits include a combination of an overvoltage detection circuit and a voltage clamping circuit that inhibits sustained overvoltage conditions. An overvoltage detection circuit can include first and second terminals electrically coupled to first and second power supply signal lines, respectively. This overvoltage detection circuit may be configured to generate a clamp activation signal (CAS) in response to detecting an excessive overvoltage between the first and second power supply signal lines. This CAS is provided to an input of the voltage clamping circuit, which is electrically coupled to the first power supply signal line and configured to sink current from the first power supply signal line in response to the CAS. The voltage clamping circuit may be configured to turn on and sink current from the first power supply signal line in-sync with a transition of the CAS from a first logic state to a second logic state.

Abstract: Systems and methods are disclosed for managing power consumption in electronic devices. In certain embodiments, an integrated circuit for managing power consumption in an electronic device includes an input/output (I/O) interface, a first circuit block coupled to the I/O interface, and an interface circuit coupled between the I/O interface and the first circuit block, the interface circuit configured to provide a defined logic state to the first circuit block or a second circuit block external to the integrated circuit if one of the first circuit block or the second circuit block is powered down. By providing a defined logic state to the first circuit block or the second circuit block when one of the first circuit block or the second circuit block is powered down, power consumption of the electronic device may be reduced.

Abstract: A static random access memory (SRAM) includes an input read register (IRR) for monitoring the state of external binary devices and an output drive register (ODR) for controlling the state of external binary devices. The SRAM can be a multi-port device for access by multiple processors or controllers. Each bit of the IRR can mirror the state of a connected external binary device. Each bit of the ODR can manipulate the state of a connected external binary device or can be read without changing the state. The memory device may include settable controlling bits and a set of controlled register bits. Setting the one or more controlling bits may define which controlled register bits are associated with the IRR and which are associated with the ODR.

Abstract: A reference output circuit for generating an output clock signal for driving signals off of an integrated circuit chip uses a switched terminated load in combination with an output buffer to generate a feedback clock signal, which is used, in combination with a reference input clock signal, to generate the output clock signal. The switched terminated load uses transistors having the same size as transistors in the output buffer. The switched terminated load draws the same DC current as the output buffer. As a result, the switched terminated load and the output buffer have the same electro-migration performance. Pull-up and pull-down MOS impedances of the switched terminated load are easily adjusted during switching periods of the switched terminated load. The design of the switched terminated load minimizes variations in the terminated load impedance due to MOS impedance variations.

Abstract: A static random access memory (SRAM) includes an input read register (IRR) for monitoring the state of external binary devices and an output drive register (ODR) for controlling the state of external binary devices. The SRAM can be a multi-port device for access by multiple processors or controllers. Each bit of the IRR can mirror the state of a connected external binary device, and can be read to a connected processor using a standard read instruction. Each bit of the ODR can manipulate the state of a connected external binary device by providing the device with a path to the SRAM supply voltage. Each bit of the ODR can also be read without changing the state, or interrupting the operation of, the connected external binary device. When set to the proper mode, the addresses used for the IRR and ODR can be used with the SRAM main memory array for standard memory operations.

Abstract: An impedance matching logic generates code values that define pull-up and pull-down transistors to be enabled with output buffers. The output buffers store the code values using a two-stage latch configuration, such that updated code values are always stored within the output buffer, even if the output buffer is driving an output signal when the updated code values are received. The impedance matching logic uses previously determined code values to shorten the time required to calculate updated code values. The impedance matching logic may be operated in response to a clock signal having a frequency lower than the frequency of the output clock signal used to control the output buffers. The impedance matching logic may adjust the code values by certain percentages using a multiplication function, thereby allowing for design fine tuning (e.g., due to layout mismatch).

Abstract: Systems and methods are disclosed for managing power consumption in electronic devices. In certain embodiments, an integrated circuit for managing power consumption in an electronic device includes an input/output (I/O) interface, a first circuit block coupled to the I/O interface, and an interface circuit coupled between the I/O interface and the first circuit block, the interface circuit configured to provide a defined logic state to the first circuit block or a second circuit block external to the integrated circuit if one of the first circuit block or the second circuit block is powered down. By providing a defined logic state to the first circuit block or the second circuit block when one of the first circuit block or the second circuit block is powered down, power consumption of the electronic device may be reduced.

Abstract: An impedance matching logic generates code values that define pull-up and pull-down transistors to be enabled with output buffers. The output buffers store the code values using a two-stage latch configuration, such that updated code values are always stored within the output buffer, even if the output buffer is driving an output signal when the updated code values are received. The impedance matching logic uses previously determined code values to shorten the time required to calculate updated code values. The impedance matching logic may be operated in response to a clock signal having a frequency lower than the frequency of the output clock signal used to control the output buffers. The impedance matching logic may adjust the code values by certain percentages using a multiplication function, thereby allowing for design fine tuning (e.g., due to layout mismatch).

Abstract: A circuit including a first stage register that operates in response to a first clock having a period TCYCLE, a programmable delay circuit that introduces a programmable delay to the first clock, thereby creating a second clock, a second stage register that operates in response to the second clock, combinational logic coupled between the first register output and the second register input, and a third register having an input coupled to the second register output. The programmable delay is selected: (1) to have a positive value if the signal delay between the first and second registers exceeds TCYCLE, and (2) such that the signal delay between the second and third registers is less than TCYCLE minus the programmable delay. Additional delayed clocks generated in response to the second clock signal can be used to operate additional second stage registers, thereby staggering the outputs of these second stage registers within TCYCLE.

Abstract: A memory system includes a plurality of memory blocks, each having a dedicated local arithmetic logic unit (ALU). A data value having a plurality of bytes is stored such that each of the bytes is stored in a corresponding one of the memory blocks. In a read-modify-write operation, each byte of the data value is read from the corresponding memory block, and is provided to the corresponding ALU. Similarly, each byte of a modify data value is provided to a corresponding ALU on a memory data bus. Each ALU combines the read byte with the modify byte to create a write byte. Because the write bytes are all generated locally within the ALUs, long signal delay paths are avoided. Each ALU also generates two possible carry bits in parallel, and then uses the actual received carry bit to select from the two possible carry bits.

Abstract: A memory system includes a plurality of memory blocks, each having a dedicated local arithmetic logic unit (ALU). A data value having a plurality of bytes is stored such that each of the bytes is stored in a corresponding one of the memory blocks. In a read-modify-write operation, each byte of the data value is read from the corresponding memory block, and is provided to the corresponding ALU. Similarly, each byte of a modify data value is provided to a corresponding ALU on a memory data bus. Each ALU combines the read byte with the modify byte to create a write byte. Because the write bytes are all generated locally within the ALUs, long signal delay paths are avoided. Each ALU also generates two possible carry bits in parallel, and then uses the actual received carry bit to select from the two possible carry bits.

Abstract: A circuit including a first stage register that operates in response to a first clock having a period TCYCLE, a programmable delay circuit that introduces a programmable delay to the first clock, thereby creating a second clock, a second stage register that operates in response to the second clock, combinational logic coupled between the first register output and the second register input, and a third register having an input coupled to the second register output. The programmable delay is selected: (1) to have a positive value if the signal delay between the first and second registers exceeds TCYCLE, and (2) such that the signal delay between the second and third registers is less than TCYCLE minus the programmable delay. Additional delayed clocks generated in response to the second clock signal can be used to operate additional second stage registers, thereby staggering the outputs of these second stage registers within TCYCLE.

Abstract: A reference output circuit for generating an output clock signal for driving signals off of an integrated circuit chip uses a switched terminated load in combination with an output buffer to generate a feedback clock signal, which is used, in combination with a reference input clock signal, to generate the output clock signal. The switched terminated load uses transistors having the same size as transistors in the output buffer. The switched terminated load draws the same DC current as the output buffer. As a result, the switched terminated load and the output buffer have the same electro-migration performance. Pull-up and pull-down MOS impedances of the switched terminated load are easily adjusted during switching periods of the switched terminated load. The design of the switched terminated load minimizes variations in the terminated load impedance due to MOS impedance variations.

Abstract: An integrated circuit device utilizes a serial scan chain register to support efficient reliability testing of internal circuitry that is not readily accessible from the I/O pins of the device. The scan chain register has scan chain latch units that support a toggle mode of operation. The scan chain register is provided with serial and parallel input ports and serial and parallel output ports. Each of the plurality of scan chain latch units includes a latch element and additional circuit elements that are configured to selectively establish a feedback path in the respective latch unit. This feedback path operates to pass an inversion of a signal at an output of the latch to an input of the latch when the corresponding scan chain latch unit is enabled to support a toggle mode of operation.

Abstract: A circuit for protecting the internal circuitry of a semiconductor chip from increased power supply voltages due to electrostatic discharge events is presented. The circuit comprises a trigger circuit including a resistor and diode array coupled between a power line and a ground line and a discharge circuit which, when turned on by an output signal of the trigger circuit, conducts the excess charge on the power line to ground.