Abstract: A memory device comprises a plurality of backend interfaces that are each configured to connect to a respective media device (e.g., DDR, LPDDR DRAM), a plurality of reliability, availability and serviceability (RAS) channel datapaths with each RAS channel datapath connected to one or more backend interfaces, one or more caches that are each connected to at least one RAS channel datapath, and control circuitry. The control circuitry is configured to: in response to receiving a memory access request for a memory location, search a cache of the one or more caches for the requested memory location; and when, in response to the search, the requested memory location is not found in the cache, obtain the requested memory location from a media device connected to the at least one RAS channel datapath. Corresponding methods are also described.

Abstract: A memory device comprises a plurality of backend interfaces that are each configured to connect to a respective media device (e.g., DDR, LPDDR DRAM), a plurality of reliability, availability and serviceability (RAS) channel datapaths with each RAS channel datapath connected to one or more backend interfaces, one or more caches that are each connected to at least one RAS channel datapath, and control circuitry. The control circuitry is configured to: in response to receiving a memory access request for a memory location, search a cache of the one or more caches for the requested memory location; and when, in response to the search, the requested memory location is not found in the cache, obtain the requested memory location from a media device connected to the at least one RAS channel datapath. Corresponding methods are also described.

Abstract: Provided is a system comprising a communication interface between a host and a device, wherein the header of a first memory request transmitted on the forward link of the communication interface encodes, in a bit vector, addresses to be read for a plurality of second memory requests. Combining one or more read requests with another request such that a single request header is transmitted for a plurality of respective requests provides for more efficient use of the forward link bandwidth. Corresponding methods are also described.

Abstract: A system comprising an interface between a host and a device, wherein the interface is configured to reorder messages to package flits to reduce or eliminate underutilized bandwidth in one or both directions of a bidirectional link. In one example, the interface is in accordance with the CXL specification, and the host and the device (e.g., a memory device) include CXL-compliant controllers to pack and unpack flits.

Abstract: A method performed by a protocol controller for packing a frame includes selecting, based on current contents of at least one message buffer, a stored packing template, and packing the frame in accordance with the selected packing template. The packing comprises packing each slot of the frame with a respective request (e.g., read request, write request) from the message buffer in accordance with the selected packing template. The template is selected from a plurality of stored packing templates. Associated host devices on which the protocol controller is arranged are also described.

Abstract: In a computer host system, a system and method to compress the transmission between the central processing unit (CPU) and the dynamic random access memory (DRAM) of either of an extended consecutive series of ‘0’ bits or an extended consecutive series of ‘1’ bits. The CPU or a Compute Express Link (CXL) Initiator associated with the CPU identifies the consecutive strings of ‘0’ bits or ‘1’ bits. The CPU or the CXL Initiator sets data flags in a FLIT data structure, using just two bits or four bits to indicate the strings. The data structure is sent to a CXL memory, which interprets the flags and constructs the extended series of ‘0’ bits or extended series of ‘1’ bits.

Abstract: Described apparatuses and methods enable a receiver of requests, such as a memory device, to modulate the arrival of future requests using a credit-based communication protocol. A transmitter of requests can be authorized to transmit a request responsive to possession of a credit corresponding to the communication request. In these situations, if the transmitter has exhausted a supply of credits, the transmitter waits until a credit is returned before transmitting another request. The receiver of the requests can manage credit returns based on whether a request queue has space to receive another request. Further, the receiver can delay a credit return based on how many requests are pending at the receiver, even if space is available in the request queue. This delay can prevent an oversupply of requests from developing downstream of the request queue. Latency, for instance, can be improved by managing the presence of requests that are downstream.

Abstract: A method includes receiving a write request to a write queue of a host having the write queue and a read queue; initiating a write queue timer upon receiving the write request to the write queue of the host, wherein the write queue timer has a write queue timer expiry threshold value; and executing one or more write requests when the write queue timer reaches the write queue timer expiry threshold value.

Abstract: Described apparatuses and methods relate to a memory-flow control register for a memory system that may support a nondeterministic protocol. To help manage the flow of memory requests in a system, a memory device can include logic, such as a hardware register, that can store values indicative of a total number of memory requests that are serviceable by the memory device at a time. The logic can be configured by device manufacturers during assembly. The manufacturers can determine the limits or capabilities of the system, based on the components and structures, and publish the capabilities, including QoS, based on the limits. When the memory device is connected to a host, the host can read the values and limit the number of memory requests sent to the device based on the values. Accordingly, the memory-flow control register can improve latency and bandwidth in accessing a memory device over an interconnect.

Abstract: Described apparatuses and methods enable a receiver of requests, such as a memory device, to control the arrival of future requests using a credit-based communication protocol. A transmitter of requests can be authorized to transmit a request across an interconnect responsive to possession of a credit. If the transmitter exhausts its credits, the transmitter waits until a credit is returned before transmitting another request. The receiver can manage credit returns based on how many responses are present in a response queue. The receiver can change a rate at which the credit returns are transmitted by changing a size of an interval of responses that are being transmitted, with one credit being returned per interval. This can slow the rate of credit returns while the response queue is relatively more filled. The rate adjustment can decrease latency by reducing an amount of requests or responses that are pooling in backend components.

Abstract: Described apparatuses and methods enable a receiver of requests, such as a memory device, to modulate the arrival of future requests using a credit-based communication protocol. A transmitter of requests can be authorized to transmit a request responsive to possession of a credit corresponding to the communication request. In these situations, if the transmitter has exhausted a supply of credits, the transmitter waits until a credit is returned before transmitting another request. The receiver of the requests can manage credit returns based on whether a request queue has space to receive another request. Further, the receiver can delay a credit return based on how many requests are pending at the receiver, even if space is available in the request queue. This delay can prevent an oversupply of requests from developing downstream of the request queue. Latency, for instance, can be improved by managing the presence of requests that are downstream.

Abstract: Described apparatuses and methods relate to a memory-flow control register for a memory system that may support a nondeterministic protocol. To help manage the flow of memory requests in a system, a memory device can include logic, such as a hardware register, that can store values indicative of a total number of memory requests that are serviceable by the memory device at a time. The logic can be configured by device manufacturers during assembly. The manufacturers can determine the limits or capabilities of the system, based on the components and structures, and publish the capabilities, including QoS, based on the limits. When the memory device is connected to a host, the host can read the values and limit the number of memory requests sent to the device based on the values. Accordingly, the memory-flow control register can improve latency and bandwidth in accessing a memory device over an interconnect.

Abstract: Described apparatuses and methods relate to a write request buffer for a memory system that may support a nondeterministic protocol. A host device and connected memory device may include a controller with a read queue and a write queue. A controller includes a write request buffer to buffer write addresses and write data associated with write requests directed to the memory device. The write request buffer can include a write address buffer that stores unique write addresses and a write data buffer that stores most-recent write data associated with the unique write addresses. Incoming read requests are compared with the write requests stored in the write request buffer. If a match is found, the write request buffer can service the requested data without forwarding the read request downstream to backend memory. Accordingly, the write request buffer can improve the latency and bandwidth in accessing a memory device over an interconnect.

Abstract: Described apparatuses and methods enable a receiver of requests, such as a memory device, to control the arrival of future requests using a credit-based communication protocol. A transmitter of requests can be authorized to transmit a request across an interconnect responsive to possession of a credit. If the transmitter exhausts its credits, the transmitter waits until a credit is returned before transmitting another request. The receiver can manage credit returns based on how many responses are present in a response queue. The receiver can change a rate at which the credit returns are transmitted by changing a size of an interval of responses that are being transmitted, with one credit being returned per interval. This can slow the rate of credit returns while the response queue is relatively more filled. The rate adjustment can decrease latency by reducing an amount of requests or responses that are pooling in backend components.

Abstract: A method includes receiving a write request to a write queue of a host having the write queue and a read queue; initiating a write queue timer upon receiving the write request to the write queue of the host, wherein the write queue timer has a write queue timer expiry threshold value; and executing one or more write requests when the write queue timer reaches the write queue timer expiry threshold value.