Memory devices and a memory controller that controls such memory devices. Multiple memory devices receive commands and addresses on a command/address (C/A) bus that is relayed point-to-point by each memory device. Data is received and sent from these devices to/from a memory controller in a point-to-point configuration by adjusting the width of each individual data bus coupled between the individual memory devices and the memory controller. Along with the C/A bus are clock signals that are regenerated by each memory device and relayed. The memory controller and memory devices may be packaged on a single substrate using package-on-package technology. Using package-on-package technology allows the relayed C/A signals to connect from memory device to memory device using wire bonding. Wirebond connections provide a short, high-performance signaling environment for the chip-to-chip relaying of the C/A signals and clocks from one memory device to the next in the daisy-chain.

A multi-channel memory system has a memory device, a plurality of channels, and a control circuit. The memory device has a plurality of memory storage spaces. The channels are coupled to the memory storage spaces, respectively, wherein each of the channels is configured to act as a memory interface for accessing a corresponding memory storage space independently. The control circuit controls clock frequencies of clocks on the channels, respectively. At a same time point, the channels include at least a first channel operating at a first clock frequency set by the control circuit and a second channel operating at a second clock frequency set by the control circuit at a same time point, and the second clock frequency is different from the first clock frequency.

An extended peripheral component interconnect express (PCIe) device includes a host PCIe fabric comprising a host root complex. The host PCIe fabric has a first set of bus numbers and a first memory mapped input/output (MMIO) space on a host CPU. An extended PCIe fabric includes a root complex endpoint (RCEP) as part of an endpoint of the host PCIe fabric. The extended PCIe fabric has a second set of bus numbers and a second MMIO space separate from the first set of bus numbers and the first MMIO space, respectively.

A cache system, having a first cache, a second cache, and a logic circuit coupled to control the first cache and the second cache according to an execution type of a processor. When an execution type of a processor is a first type indicating non-speculative execution of instructions and the first cache is configured to service commands from a command bus for accessing a memory system, the logic circuit is configured to copy a portion of content cached in the first cache to the second cache. The cache system can include a configurable data bit. The logic circuit can be coupled to control the caches according to the bit. Alternatively, the caches can include cache sets. The caches can also include registers associated with the cache sets respectively. The logic circuit can be coupled to control the cache sets according to the registers.

A central processor unit (CPU) is connected to a system/graphics controller generally comprising a monolithic semiconductor device. The system/graphics controller is connected to an input output (IO) controller via a high-speed PCI bus. The IO controller interfaces to the system graphics controller via the high-speed PCI bus. The IO controller includes a lower speed PCI port controlled by an arbiter within the IO controller. Generally, the low speed PCI arbiter of the IO controller will interface to standard 33 MHz PCI cards. In addition, the IO controller interfaces to an external storage device, such as a hard drive, via either a standard or a proprietary bus protocol. A unified system/graphics memory which is accessed by the system/graphics controller. The unified memory contains both system data and graphics data. In a specific embodiment, two channels, CH0 and CH1 access the unified memory. Each channel is capable of accessing a portion of memory containing graphics data or a portion of memory containing system data.

A processing element/unit can include a plurality of networks, a plurality of cores, crossbar interconnects, a plurality of memory controllers and local memory on an integrated circuit (IC) chip. The plurality of cores can be coupled together by the plurality of networks on chip. The crossbar interconnects can couple the networks of cores to the plurality of memory controllers. The plurality of memory controllers can be configured to access data stored in off-chip memory. The local memory can be configured to cache portions of the accessed data. The local memory can be directly accessible by the network of processing cores, or can be distributed across the plurality of memory controllers. The memory controllers can be narrow channel (NC) memory controllers having widths of 4, 8, 12, 16 or a multiple of 4 bits.

A memory channel includes a dual channel double data rate (DDR) memory device having a first bank of memory accessed by a first data bus and a first command/address (C/A) bus, and a second bank of memory accessed by a second data bus and a second C/A bus, and a memory controller configured to train the first and second C/A busses with both the first and second C/A busses active, and to train one of the first and second C/A busses with the other of the first and second C/A busses idle.

Provided are a parallel processing system and an operation method thereof. The parallel processing system includes: a bus; a plurality of parallel processing processors; a plurality of shared memories connected to the bus via separate individual channels and connected to each other via a memory connection line; and a main processor configured to set a broadcasting state for the plurality of shared memories and control data stored in one shared memory among the plurality of shared memories to be broadcast to another shared memory via the memory connection line according to the broadcasting state.

A semiconductor device performs a software lock-step. The semiconductor device includes a first circuit group including a first Intellectual Property (IP) to be operated in a first address space, a first bus, and a first memory, a second circuit group including a second IP to be operated in a second address space, a second bus, and a second memory, a third bus connectable to a third memory, and a transfer control circuit coupled to the first to third buses. when the software lock-step is performed, the second circuit group converts an access address from the second IP to the second memory such that an address assigned to the second memory in the second address space is a same as an address assigned to the first memory in the first address space.

A memory controller for dual-channel DDR DIMMs comprises a first memory channel configured to execute a first memory transaction with a first memory device of a dual-channel DDR DIMM, and a second memory channel configured to execute a second memory transaction with a second memory device of the dual-channel DDR DIMM. The memory controller is configured to determine that the first memory channel is experiencing a degraded performance level in executing the first memory transaction with the first device, and to prevent read-write memory transactions and write-read memory transactions on the first and second memory channels in response to determining that the first memory channel is experiencing the degraded performance level.