摘要:
A computer system comprises a direct memory access (DMA) transfer unit and a plurality of DMA devices coupled by an external bus. The DMA transfer unit effectuates DMA transfers for the plurality of DMA devices. The DMA transfer unit contains a DMA controller, a bus arbiter, and a bus controller. The DMA controller and the bus controller generate a two-clock cycle DMA transfer. To effectuate a two-clock cycle DMA transfer, a requesting DMA device sets-up a DMA transfer with the DMA controller such that a DACK# signal is asserted during a first clock period. During a second clock period, the DMA controller sets-up the memory address. During a third clock period, the bus controller transitions a command signal on the external bus. Upon assertion of the command signal, valid data is asserted on the external bus. For demand and block mode operations, additional DMA transfers are executed in a two-clock cycle DMA transfer. The DMA controller and the bus controller also generate a three-clock cycle DMA transfer.
摘要:
A hardware-based digital random number generator is provided. The digital random number generator is a randomly behaving random number generator based on a set of nondeterministic behaviors. The nondeterministic behaviors include temporal asynchrony between subunits, entropy source “extra” bits, entropy measurement, autonomous deterministic random bit generator reseeding and consumption from a shared resource.
摘要:
Apparatuses and methods for supervisor mode execution protection are disclosed. In one embodiment, a processor includes an interface to access a memory, execution hardware, and control logic. A region in the memory is user memory. The execution hardware is to execute an instruction. The control logic is to prevent the execution hardware from executing the instruction when the instruction is stored in user memory and the processor is in supervisor mode.
摘要:
A method, apparatus and system are disclosed for decoding an instruction in a variable-length instruction set. The instruction is one of a set of new types of instructions that uses a new escape code value, which is two bytes in length, to indicate that a third opcode byte includes the instruction-specific opcode for a new instruction. The new instructions are defined such the length of each instruction in the opcode map for one of the new escape opcode values may be determined using the same set of inputs, where each of the inputs is relevant to determining the length of each instruction in the new opcode map. For at least one embodiment, the length of one of the new instructions is determined without evaluating the instruction-specific opcode.
摘要:
A method, apparatus and system are disclosed for decoding an instruction in a variable-length instruction set. The instruction is one of a set of new types of instructions that uses a new escape code value, which is two bytes in length, to indicate that a third opcode byte includes the instruction-specific opcode for a new instruction. The new instructions are defined such the length of each instruction in the opcode map for one of the new escape opcode values may be determined using the same set of inputs, where each of the inputs is relevant to determining the length of each instruction in the new opcode map. For at least one embodiment, the length of one of the new instructions is determined without evaluating the instruction-specific opcode.
摘要:
Apparatuses and methods for supervisor mode execution protection are disclosed. In one embodiment, a processor includes an interface to access a memory, execution hardware, and control logic. A region in the memory is user memory. The execution hardware is to execute an instruction. The control logic is to prevent the execution hardware from executing the instruction when the instruction is stored in user memory and the processor is in supervisor mode.
摘要:
A method, apparatus and system are disclosed for decoding an instruction in a variable-length instruction set. The instruction is one of a set of new types of instructions that uses a new escape code value, which is two bytes in length, to indicate that a third opcode byte includes the instruction-specific opcode for a new instruction. The new instructions are defined such the length of each instruction in the opcode map for one of the new escape opcode values may be determined using the same set of inputs, where each of the inputs is relevant to determining the length of each instruction in the new opcode map. For at least one embodiment, the length of one of the new instructions is determined without evaluating the instruction-specific opcode.
摘要:
A direct memory access (DMA) circuit includes a first register for storing an address for the transfer of data, apparatus for transferring data at sequential addresses beginning at the address in the first register until all data at sequential addresses has been transferred, a second register for storing a beginning address for a list of addresses, and a state machine which responds to the completion of a transfer of data at sequential addresses beginning at the address in the first register and an indication that more data is to be transferred to transfer an address from the list at the address in the second register to the first register and causes the apparatus for transferring data to commence.
摘要:
Embodiments of systems, apparatuses, and methods for performing privilege agnostic segment base register read or write instruction are described. An exemplary method may include fetching the privilege agnostic segment base register write instruction, wherein the privilege agnostic write instruction includes a 64-bit data source operand, decoding the fetched privilege agnostic segment base register write instruction, and executing the decoded privilege agnostic segment base register write instruction to write the 64-bit data of the source operand into the segment base register identified by the opcode of the privilege agnostic segment base register write instruction.
摘要:
A hardware-based digital random number generator is provided. The digital random number generator is a randomly behaving random number generator based on a set of nondeterministic behaviors. The nondeterministic behaviors include temporal asynchrony between subunits, entropy source “extra” bits, entropy measurement, autonomous deterministic random bit generator reseeding and consumption from a shared resource.