Abstract: A memory control circuit coupled to multiple memory ranks may receive read and write requests for a different ranks of the multiple memory ranks. The memory control may allocate write requests to different slots based on the write requests target memory rank, and may adjust the number of slots available for a given memory rank during a write turn to improve write efficiency. The memory control circuit may also determine a number of ranks switches within a read turn based on whether a particular quality-of-service requirement associated with the read requests is being satisfied.

Abstract: A memory control circuit coupled to multiple memory ranks may receive read and write requests for a different ranks of the multiple memory ranks. The memory control may allocate write requests to different slots based on the write requests target memory rank, and may adjust the number of slots available for a given memory rank during a write turn to improve write efficiency. The memory control circuit may also determine a number of ranks switches within a read turn based on whether a particular quality-of-service requirement associated with the read requests is being satisfied.

Abstract: Techniques are disclosed relating to memory error tracking and logging. In some embodiments, a memory cache controller circuitry is configured to track, using multiple circuit entries, numbers of detected correctable errors associated with multiple respective locations, and in response to detecting a threshold number of correctable errors for a particular location, generate a signal to the one or more processors that identifies the particular location. In some embodiments, the memory cache controller circuitry includes multiple circuit entries for tracking uncorrectable errors.

Abstract: Techniques for scheduling memory operations are disclosed in which alternate read/write commands within a multi-bank memory operation are delayed beyond a minimum timing parameter in order to increase memory data bus utilization. The remaining read/write commands are not delayed beyond the minimum timing parameter. Every other clock cycle (e.g., even clock cycles) within the memory operation is reserved for activate commands, while other commands such as sync and read/write are scheduled on the intervening clock cycles (e.g., odd clock cycles). For memory devices for which a sync command (which causes a clock of the memory data bus to start) is to precede a corresponding read/write command by a number of clock cycles that would place it in a cycle reserved for activate commands, a particular operation mode is disclosed in which the memory device internally delays a received sync command.

Abstract: Systems, apparatuses, and methods for addressing bank hotspotting are described. A computing system includes a memory controller with an arbiter for determining how to arbitrate access to one or more memory device(s) for received requests. The arbiter categorizes each request in a manner that helps to ensure fair virtual channel distribution across the banks of the memory device(s). The category system includes bank hotspotting functions to give banks that have more requests more chances to go over banks with fewer requests. The category system is implemented proportionally with more category credits given to banks with higher bank depths within the virtual channel.

Abstract: Techniques are disclosed relating to multi-activation techniques for wire operations with multiple partial writes. In some embodiments, a memory controller is configured to access data in a memory device that supports partial writes having a first size using read-modify-write operations and non-partial writes having a second size that is greater than the first size. In some embodiments, the memory controller is configured to queue a first write operation having the second size, where the first write operation includes multiple partial writes. In some embodiments, the memory controller is configured to send separate activate signals to the memory device to activate a bank of the memory device to perform different proper subsets of the multiple partial writes. This may allow interleaving of other accesses to a memory bank and merging of writes while waiting for a current activation, in some embodiments.

Abstract: Techniques are disclosed relating to improving memory reliability, e.g., in the context of memory circuits with limited reliability features. In some embodiments, memory controller circuitry is configured to communicate with memory circuitry via an interface that supports link error detection. The memory controller circuitry may, based on a corruption indicator, transmit a data and parity combination for the first data block that causes the memory circuitry to detect an uncorrectable write interface error. Subsequent reads of the location may therefore cause an uncorrectable error indication. This may advantageously allow the memory controller circuitry to propagate a corruption indicator as an uncorrectable error in the memory circuit, without requiring additional tracking of the indicator by the memory circuit or memory controller, in some embodiments.

Abstract: Techniques are disclosed relating to merging virtual communication channels in a portion of a computing system. In some embodiments, a communication fabric routes first and second classes of traffic with different quality-of-service parameters, using a first virtual channel for the first class and a second virtual channel for the second class. In some embodiments, a memory controller communicates, via the fabric, using a merged virtual channel configured to handle traffic from both the first virtual channel and the second virtual channel. In some embodiments, the system limits the rate at which an agent is allowed to transmit requests of the second class of traffic, but requests by the agent for the first class of traffic are not rate limited. Disclosed techniques may improve independence of virtual channels, relative to sharing the same channel in an entire system, without unduly increasing complexity.

Abstract: Techniques are disclosed relating to improving memory reliability. In some embodiments, memory circuitry includes memory cells configured to store data, interface circuitry, and on-die error correcting code (ECC) circuitry. The ECC circuitry may check read data from the memory cells for errors and correct detected correctable errors to generate corrected data. The memory circuitry may provide read data to a requesting circuit via the interface circuitry, including one or more sets of corrected data from the on-die ECC circuitry. The memory circuitry may provide a decoding status flag (DSF) via the interface circuitry, including to: set the DSF to a first value in response to no error being detected for a given set of provided read data, set the DSF to a second value in response to a correctable error that was detected and corrected by the on-die ECC circuitry to provide a given set of read data, and set the DSF to a third value in response to an uncorrectable error detected by the on-die ECC circuitry.

Abstract: Techniques are disclosed relating to memory error tracking and logging. In some embodiments, a memory cache controller circuitry is configured to track, using multiple circuit entries, numbers of detected correctable errors associated with multiple respective locations, and in response to detecting a threshold number of correctable errors for a particular location, generate a signal to the one or more processors that identifies the particular location. In some embodiments, the memory cache controller circuitry includes multiple circuit entries for tracking uncorrectable errors.

Abstract: Techniques are disclosed relating to improving memory reliability, e.g., in the context of memory circuits with limited reliability features. In some embodiments, memory controller circuitry is configured to communicate with memory circuitry via an interface that supports link error detection. The memory controller circuitry may, based on a corruption indicator, transmit a data and parity combination for the first data block that causes the memory circuitry to detect an uncorrectable write interface error. Subsequent reads of the location may therefore cause an uncorrectable error indication. This may advantageously allow the memory controller circuitry to propagate a corruption indicator as an uncorrectable error in the memory circuit, without requiring additional tracking of the indicator by the memory circuit or memory controller, in some embodiments.

Abstract: Techniques are disclosed relating to multi-activation techniques for wire operations with multiple partial writes. In some embodiments, a memory controller is configured to access data in a memory device that supports partial writes having a first size using read-modify-write operations and non-partial writes having a second size that is greater than the first size. In some embodiments, the memory controller is configured to queue a first write operation having the second size, where the first write operation includes multiple partial writes. In some embodiments, the memory controller is configured to send separate activate signals to the memory device to activate a bank of the memory device to perform different proper subsets of the multiple partial writes. This may allow interleaving of other accesses to a memory bank and merging of writes while waiting for a current activation, in some embodiments.

Abstract: Techniques for scheduling memory operations are disclosed in which alternate read/write commands within a multi-bank memory operation are delayed beyond a minimum timing parameter in order to increase memory data bus utilization. The remaining read/write commands are not delayed beyond the minimum timing parameter. Every other clock cycle (e.g., even clock cycles) within the memory operation is reserved for activate commands, while other commands such as sync and read/write are scheduled on the intervening clock cycles (e.g., odd clock cycles). For memory devices for which a sync command (which causes a clock of the memory data bus to start) is to precede a corresponding read/write command by a number of clock cycles that would place it in a cycle reserved for activate commands, a particular operation mode is disclosed in which the memory device internally delays a received sync command.

Abstract: Techniques are disclosed relating to merging virtual communication channels in a portion of a computing system. In some embodiments, a communication fabric routes first and second classes of traffic with different quality-of-service parameters, using a first virtual channel for the first class and a second virtual channel for the second class. In some embodiments, a memory controller communicates, via the fabric, using a merged virtual channel configured to handle traffic from both the first virtual channel and the second virtual channel. In some embodiments, the system limits the rate at which an agent is allowed to transmit requests of the second class of traffic, but requests by the agent for the first class of traffic are not rate limited. Disclosed techniques may improve independence of virtual channels, relative to sharing the same channel in an entire system, without unduly increasing complexity.

Abstract: Systems, apparatuses, and methods for addressing bank hotspotting are described. A computing system includes a memory controller with an arbiter for determining how to arbitrate access to one or more memory device(s) for received requests. The arbiter categorizes each request in a manner that helps to ensure fair virtual channel distribution across the banks of the memory device(s). The category system includes bank hotspotting functions to give banks that have more requests more chances to go over banks with fewer requests. The category system is implemented proportionally with more category credits given to banks with higher bank depths within the virtual channel.

Abstract: An apparatus includes a memory circuit and a memory controller circuit. The memory controller circuit may include a write request queue. The memory controller circuit may be configured to receive a memory request to access the memory circuit and determine if the memory request includes a read request or a write request. A received read request may be scheduled for execution, while a received write request may be stored in the write request queue. The memory controller circuit may reorder scheduled memory requests based on achieving a specified memory access efficiency and based on a number of write requests stored in the write request queue.

Abstract: Techniques relating to arbitration in a memory controller are disclosed. In some embodiments, the memory controller is configured to transition between read turns and writes turn according to a turn schedule. In some embodiments, the memory controller also receives reports from circuitry requesting memory transactions and determines a current latency tolerance value based on the reports. In some embodiments, the memory controller is configured to switch from a write turn to a read turn prior to a scheduled switch based on the current latency tolerance meeting a threshold value.

Abstract: A memory controller circuit coupled to a memory circuit that includes multiple banks may receive multiple access requests including a particular access request to a particular bank of the plurality of banks. The particular access request is associated with a particular virtual channel of a plurality of virtual channels. The memory controller circuit may select a given access requests of the multiple access requests based on an arbitration category value associated with a virtual channel of the given access request and modify the arbitration category value in response to selecting the given access request.

Abstract: A memory controller circuit coupled to multiple memory circuits may receive requests to access particular locations within the multiple memory circuits. A request may be assigned a particular quality-of-service level. During operation, the memory controller circuit may reallocate the quality-of-service level of a particular request to a new quality-of-service level based on accumulated bandwidth credits associated with the new quality-of-service level.

Abstract: A memory controller circuit coupled to multiple memory circuits may receive a read request for a particular one of the memory circuits and insert the read request into one of multiple linked lists that includes a linked list whose entries correspond to previously received read requests and are linked according to respective ages of the read requests. The memory controller circuit may schedule the read request using a head pointer of one of the multiple linked lists.