Memory controller with staggered request signal output

    公开(公告)号:US10902891B2

    公开(公告)日:2021-01-26

    申请号:US16805529

    申请日:2020-02-28

    Applicant: Rambus Inc.

    Abstract: A memory controller having a time-staggered request signal output. A first timing signal is generated while a second timing signal is generated having a first phase difference relative to the first timing signal. An address value is transmitted in response to the first timing signal and a control value is transmitted in response to the second timing signal, the address value and control value constituting portions of a first memory access request.

    MEMORY WITH ALTERNATIVE COMMAND INTERFACES

    公开(公告)号:US20210011876A1

    公开(公告)日:2021-01-14

    申请号:US16942970

    申请日:2020-07-30

    Applicant: Rambus Inc.

    Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.

    Cache memory that supports tagless addressing

    公开(公告)号:US10891241B2

    公开(公告)日:2021-01-12

    申请号:US16149553

    申请日:2018-10-02

    Applicant: Rambus Inc.

    Abstract: The disclosed embodiments relate to a computer system with a cache memory that supports tagless addressing. During operation, the system receives a request to perform a memory access, wherein the request includes a virtual address. In response to the request, the system performs an address-translation operation, which translates the virtual address into both a physical address and a cache address. Next, the system uses the physical address to access one or more levels of physically addressed cache memory, wherein accessing a given level of physically addressed cache memory involves performing a tag-checking operation based on the physical address. If the access to the one or more levels of physically addressed cache memory fails to hit on a cache line for the memory access, the system uses the cache address to directly index a cache memory, wherein directly indexing the cache memory does not involve performing a tag-checking operation and eliminates the tag storage overhead.

    Margin Test Methods and Circuits
    236.
    发明申请

    公开(公告)号:US20210006341A1

    公开(公告)日:2021-01-07

    申请号:US16930526

    申请日:2020-07-16

    Applicant: Rambus Inc.

    Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.

    Edge enhancement for signal transmitter

    公开(公告)号:US10887137B2

    公开(公告)日:2021-01-05

    申请号:US16817171

    申请日:2020-03-12

    Applicant: Rambus Inc.

    Abstract: A signal transmitter circuit includes an output driver circuit configured to transmit a signal using a multi-level pulse amplitude modulation (PAM) scheme comprising a plurality of discreet signal levels. During operation, the output driver initiates a first transition of the signal to a first level of the multi-level PAM scheme from a second level of the multi-level PAM scheme, and initiates a second transition of the signal to the first level from a third level of the multi-level PAM scheme. The signal transmitter further includes a control circuit configured to control a slew rate of the signal transmitter circuit to cause the signal to reach a threshold voltage level at a first time, the first time occurring a first duration of time after the first transition is initiated, and to cause the signal to reach the threshold voltage level at a second time, the second time occurring the first duration of time after the second transition is initiated.

    Multi-die memory device
    238.
    发明授权

    公开(公告)号:US10885971B2

    公开(公告)日:2021-01-05

    申请号:US16823122

    申请日:2020-03-18

    Applicant: Rambus Inc.

    Abstract: A memory is disclosed that includes a logic die having first and second memory interface circuits. A first memory die is stacked with the logic die, and includes first and second memory arrays. The first memory array couples to the first memory interface circuit. The second memory array couples to the second interface circuit. A second memory die is stacked with the logic die and the first memory die. The second memory die includes third and fourth memory arrays. The third memory array couples to the first memory interface circuit. The fourth memory array couples to the second memory interface circuit. Accesses to the first and third memory arrays are carried out independently from accesses to the second and fourth memory arrays.

    Stacked DRAM device and method of manufacture

    公开(公告)号:US10885946B2

    公开(公告)日:2021-01-05

    申请号:US16801990

    申请日:2020-02-26

    Applicant: Rambus Inc.

    Inventor: Thomas Vogelsang

    Abstract: A memory device includes a first dynamic random access memory (DRAM) integrated circuit (IC) chip including first memory core circuitry, and first input/output (I/O) circuitry. A second DRAM IC chip is stacked vertically with the first DRAM IC chip. The second DRAM IC chip includes second memory core circuitry, and second I/O circuitry. Solely one of the first DRAM IC chip or the second DRAM IC chip includes a conductive path that electrically couples at least one of the first memory core circuitry or the second memory core circuitry to solely one of the first I/O circuitry or the second I/O circuitry, respectively.

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