摘要:
A method and apparatus for processing pipelined command packets in a packetized memory device. The command packets are initially stored in one of several command units, and the commands are subsequently coupled to a common command processor for execution. The command units each include a latch for storing a command packet, a counter, and a start command generator. The counter is preloaded with a count corresponding to the timing that the command is received at a location within the memory device. The counter begins counting responsive to a flag bit received with the command packet. The start command generator receives the count of the counter, and decodes different counts depending on the type of command (e.g., a “read” or a “write”) and the speed of a clock signal that is used to control the operation of the memory device. When the start command generator decodes a count, it latches command bits of the applied command packet and generates a start command signal. Thus, the start command signal is generated after the flag signal by a delay that corresponds to the type of memory command and the clock speed. The latched command bits and the start command signal are applied to a command processor that executes the commands in a pipeline using a sequencer to generate a sequence of timing signals, and generates command signals from the latched command bits. The specific timing signal used is a function of the type of memory operation corresponding to the command bits and the clock speed. The command processor generates and applies an acknowledgment signal to the command unit upon receipt of the start command signal. The command unit is available to receive a new command upon receipt of the acknowledgment signal.
摘要:
A method and apparatus for processing pipelined command packets in a packefized memory device. The command packets are initially stored in one of several command units, and the commands are subsequently coupled to a common command processor for execution. The command units each include a latch for storing a command packet, a counter, and a start command generator. The counter is preloaded with a count corresponding to the timing that the command is received at a location within the memory device. The counter begins counting responsive to a flag bit received with the command packet. The start command generator receives the count of the counter, and decodes different counts depending on the type of command (e.g., a “read” or a “write”) and the speed of a clock signal that is used to control the operation of the memory device. When the start command generator decodes a count, it latches command bits of the applied command packet and generates a start command signal. Thus, the start command signal is generated after the flag signal by a delay that corresponds to the type of memory command and the clock speed. The latched command bits and the start command signal are applied to a command processor that executes the commands in a pipeline using a sequencer to generate a sequence of timing signals, and generates command signals from the latched command bits. The specific timing signal used is a function of the type of memory operation corresponding to the command bits and the clock speed. The command processor generates and applies an acknowledgment signal to the command unit upon receipt of the start command signal. The command unit is available to receive a new command upon receipt of the acknowledgment signal.
摘要:
A method and system for bypassing command pipelines in a pipelined memory command generator is used whenever commands must be generated with a latency that is shorter than the latency at which commands can be generated using the command pipelines. The timing of commands issued by the command pipelines is a function of a digital word, and the digital word therefore indicates the latency of the command generator. When the digital word corresponds to a latency that is shorter than the latency at which the command pipeline can generate commands for read and write operations, a bypass circuit—rather than the command pipeline—generates the commands. The bypass circuit is capable of generating the commands with a latency that is shorter than the latency at which the command pipeline is capable of issuing the commands. In addition to issuing the commands, the bypass circuit generates an inhibit signal to prevent the command pipelines from generating duplicate commands.
摘要:
A method and apparatus for electrically coupling bond pads on the surface of a microelectronic device. The apparatus can include a microelectronic device having at least two bond pads with a conductive member extending between the bond pads, external to the device. In one embodiment, the conductive member can be connected directly to the bond pads and can extend between the bond pads at or above the surface of the microelectronic device. In another embodiment, the conductive member can be connected on top of another conductive member previously attached to one of the bond pads. The conductive members can be attached to each other or to the bond pads with either ball bonds or wedge bonds to provide electrical signals to selected bond pads of the microelectronic device.
摘要:
A memory device includes an output data path that uses single-ended data in conjunction with a flag signal. The output data path transfers data from an I/O circuit coupled to a memory array to an output tri-state buffer. A comparing circuit compares data from the I/O circuit to a desired data pattern if the data does not match the desired pattern outputs the flag signal. The flag signal is input to the output buffer and the output buffer outputs a tri-state condition on the data bus. Since the flag signal corresponds to more than one data bit, the tri-state condition of the output buffer is held for more than one tick of the data clock, rather than only a single tick. Consequently, the tri-state condition remains on the bus for sufficiently long that a test system can detect the tri-state condition even at very high clock frequencies.
摘要:
A memory circuit is described which includes memory cells for storing data. The memory circuit can be read from or written to by an external system such as a microprocessor or core logic chip set. The microprocessor provides memory cell address data to the memory circuit and can request that data be output on communication lines for reading therefrom. The memory circuit reduces the time needed to read data stored in the memory by providing a valid output data signal. The valid output data signal indicates that data coupled to the communication lines has stabilized and is therefore valid. Different valid output data signals and trigger circuits for producing the signals are described.
摘要:
A command buffer for use in packetized DRAM includes a two stage shift register for shifting for sequentially storing two of the four 10-bit command words in each packet. After the first two words of each packet have been shifted into the shift register, they are transferred to a first storage register and output from the first storage register. After the final two words of each packet have been shifted into the shift register, they are transferred to a second storage register and output from the second storage register. The first two command words are output from the first storage register before the last two command words are applied to the command buffer. As a result, the DRAM can start processing the first two command words of the command packet before the entire command packet has been received. The command buffer also includes circuitry for determining whether a command packet is intended for the memory device containing the command buffer or whether it is intended for another memory device.
摘要:
A delay-locked loop incorporates binary-coupled capacitors in a capacitor bank to produce a variable capacitance along a delay line. The variable capacitance allows a delay of the variable delay line to be varied. In response to an input clock signal, the variable delay line produces a delayed output clock signal that is compared at a race detection circuit to the input clock signal. If the delayed clock signal leads the input clock signal, the race detection circuit increments a counter that controls the binary-coupled capacitors. The incremented counter increases the capacitance by coupling additional capacitance to the variable delay line to delay propagation of the delayed clock signal. If the delayed clock signal lags the original clock signal, the race detection circuit decrements the counter to decrease the capacitance, thereby decreasing the delay of the variable delay line. The race detection circuit includes an arbitration circuit that detects when the delayed clock signal and the variable clock signal are substantially synchronized and disables incrementing or decrementing of the counter in response.
摘要:
A clock generator circuit for an integrated circuit includes a phase detector comparing the phase of a delayed external clock signal to the phase of an internal clock signal. An error signal corresponding to the difference in phase between the two clock signals is applied to a differential amplifier where the error signal is offset by a value corresponding to the delay of an external clock signal as it is coupled to the phase detector. The offset error signal is applied to a control input of a voltage controlled oscillator which generates the internal clock signal. The phase of the internal clock signal it thus adjusted so that it is substantially the same as the phase of the external clock signal before being delayed as it is coupled to the phase detector and other circuitry in the integrated circuit. The voltage controlled oscillator is constructed to operate in a plurality of discrete frequency bands so that the offset error signal need only control the frequency of the internal clock signal over a relatively small range. The frequency band is selected by a signal from a register that is programmed by a user with data identifying the frequency of the external clock signal.
摘要:
A voltage level translator is disclosed which translates a CMOS input signal into a CMOS output signal where the low voltage level of the output signal is equal to the high voltage level of the input signal. The voltage level translator is described in an integrated circuit such as memory circuits, including DRAMs. Specifically, the voltage level translator produces an output signal which can be used as a gate voltage on a precharge transistor for a booted circuit where the gate voltage need only drop to the high voltage level of the input signal to shut the transistor off. The voltage level translator described, therefore, reduces the time and power required to translate an input signal by limiting the voltage swing of the output signal.