Xilinx, Inc.

Intel Corporation

Nishit Patel

James J Murray

Sagheer Ahmad

Ahmad R Ansari

Ygal Arbel

Ian A Swarbrick

Stephen S Chang

Ting Lu

Sreedhar Ravipalli

Teng Wang

Hyun Kwon

In connection with an access of content from a cache, a snoop request can be sent to one or more remote cache devices to determine if any other cache has a copy of the content. A link between the cache and the remote cache devices can include a snoop bypass device. The snoop bypass device can monitor content cached by the one or more remote devices on a cache line or coarser granularity. The snoop bypass device can respond to the snoop request with a negative indication based on a coarser granularity tracking of content of the one or more remote cache devices.

Management of cache use requests sent to remote cache devices

An example multi-master system in a system-on-chip (SoC) includes a plurality of master circuits, an error-correcting code (ECC) proxy bridge comprising hardened circuitry in the SoC, a local interconnect configured to couple the plurality of master circuits to the ECC proxy bridge, a memory not having ECC support, and a system interconnect configured to couple the ECC proxy bridge to the memory. The ECC proxy bridge is configured to establish an ECC proxy region in the memory and, for each write transaction from the plurality of master circuits that targets the ECC proxy region, calculate and insert ECC bytes into the respective write transaction.

ECC proxy extension and byte organization for multi-master systems

Methods and systems are disclosed for transferring data using descriptors to reference memory locations at which data is to be written to or read from. Each descriptor references a respective linked list of descriptor blocks. Each of the descriptor blocks includes a contiguous portion of the memory that stores a plurality of addresses, at which data is to be written to or read from. In response to receiving the data transfer request, a set of data is transferred from a first set of addresses specified in a first descriptor to a second set of addresses specified in a second descriptor by traversing the linked lists of descriptor blocks in the first and second descriptors.

Direct memory access descriptor

In an example, a circuit to manage memory between a first and second microprocessors each of which is coupled to a control circuit, includes: first and second memory circuits; and a switch circuit coupled to the first and second memory circuits, and memory interfaces of the first and second microprocessors, the switch circuit having a mode signal as input. The switch is configured to selectively operate in one of a first mode or a second mode based on the mode signal such that, in the first mode, the switch circuit couples the first memory circuit to the memory interface of the first microprocessor and the second memory circuit to the memory interface of the second microprocessor and, in the second mode, the switch circuit selectively couples the first or second memory circuits to the memory interface of either the first or second microprocessor.

Managing memory in a multiprocessor system

Circuits and methods are disclosed that allow devices to control the flow of DMA transfers to or from the devices using a token based protocol. In one example implementation, a DMA circuit includes a transfer control circuit that performs data transfers over a first data channel of a device, when transactions on the first data channel are enabled. The DMA circuit includes a flow control circuit that increments a token count for a data channel of a device when a token for the data channel is received and decrements the token count for each data transfer on the data channel performed by the DMA circuit. The flow control circuit enables data transfers on the data channel when the token count is greater than 0, and otherwise, disables data transfers on the data channel.

Flow control for direct memory access transfers

In approaches for correction of errors introduced in an interconnect circuit, an ECC proxy circuit is coupled between a first interconnect and the second interconnect, and generates for each of the write transactions from a bus master circuit, a first ECC from and associated with data of the write transaction, and transmits the write transaction and associated first ECC on the second interconnect. The ECC proxy circuit also supplements each of the read transactions from the bus master circuit with a reference to a second ECC associated with data referenced by the read transaction. The ECC proxy circuit transmits the read transaction that references the second ECC on the second interconnect. At least one random access memory (RAM) is coupled to the ECC proxy circuit through the second interconnect. The RAM stores data of each write transaction and the first ECC.

Error correction for interconnect circuits

A circuit for enabling access to data is described. The circuit comprises a memory device storing data blocks having a first predetermined size; and a direct memory access circuit coupled to the memory device, the direct memory circuit accessing a data payload having a second predetermined size which is greater than the first predetermined size; wherein the direct memory access circuit accesses the data payload in response to a descriptor having a plurality of addresses corresponding to a predetermined number of the data blocks stored in the memory device. A method of enabling the access to data is also disclosed.

Growing community of inventors

San Jose, CA, United States of America

Nishit Patel