摘要:
A method and apparatus for using dynamic programmable logic arrays in microprocessor control logic provide decreased power and increased clock frequencies for data processing systems, by using programmable logic arrays exclusively for the control logic. The method and apparatus further simplify the design of the control logic and closure of timing within the microprocessor, by providing overlap of control logic evaluations and data transfers within the microprocessor.
摘要:
A method and apparatus for synthesizing logic circuits with synchronized outputs is disclosed. A logic designer selects a fixed number of levels in which to synthesize the circuit, each level implementing a plurality of different logic function all having the same propagation delay. Circuit outputs are synchronized by ensuring that each logic function is synthesized by connecting logic functions from level to level such that each signal path passes through each level once and only once.
摘要:
The circuit library available for logic synthesis is limited to a single dynamic circuit block or logic synthesis block. The circuit design method includes first defining the logic synthesis block and then performing logic synthesis for a predetermined logical operation to be implemented. The logic synthesis step constrained to the single logic synthesis block produces an intermediate circuit design which necessarily comprises a series of dynamic circuit blocks, each associated with a single reset signal. Once the intermediate circuit is produced, the circuit design method includes eliminating unnecessary devices from the intermediate circuit to produce a final logic circuit, and then sizing the devices in the final circuit to complete the design.
摘要:
The circuit library available for logic synthesis is limited to a single dynamic circuit block or logic synthesis block. The circuit design method includes first defining the logic synthesis block and then performing logic synthesis for a predetermined logical operation to be implemented. The logic synthesis step constrained to the single logic synthesis block produces an intermediate circuit design which necessarily comprises a series of dynamic circuit blocks, each associated with a single reset signal. Once the intermediate circuit is produced, the circuit design method includes eliminating unnecessary devices from the intermediate circuit to produce a final logic circuit, and then sizing the devices in the final circuit to complete the design.
摘要:
The circuit library available for logic synthesis is limited to a single dynamic circuit block or logic synthesis block. The circuit design method includes first defining the logic synthesis block (16) and then performing logic synthesis (17) for a predetermined logical operation to be implemented. The logic synthesis step constrained to the single logic synthesis block produces an intermediate circuit design (29) which necessarily comprises a series of dynamic circuit blocks, each associated with a single reset signal. Once the intermediate circuit (29) is produced, the circuit design method includes eliminating unnecessary devices (46) from the intermediate circuit (29) to produce a final logic circuit, and then sizing the devices (48) in the final circuit to complete the design.
摘要:
A system for a processor with memory with combined line and word access is presented. A system performs narrow read/write memory accesses and wide read/write memory accesses to the same memory bank using multiplexers and latches to direct data. The system processes 16 byte load/sore requests using a narrow read/write memory access and also processes 128 byte DMA and instruction fetch requests using a wide read/write memory access. During DMA requests, the system writes/reads sixteen DMA operations to memory on one instruction cycle. By doing this, the memory is available to process load/store or instruction fetch requests during fifteen other instruction cycles.
摘要:
A method and apparatus for adding and multiplying floating-point operands such that a fixed-size mantissa result is produced. In accordance with the present addition method, the mantissa of a first floating-point operand is shifted in accordance with relative operand exponent information. Next, the first operand mantissa is added to the second operand mantissa. The addition step includes replacing a least significant non-overlapped portion of the first operand mantissa with a randomly-generated carry-in bit. In accordance with the multiplication method, a partial product array is generated from a pair of floating-point operand mantissas. Next, prior to compressing the partial product array into a compressed mantissa result, a lower-order bit portion of the partial product array is replaced with a randomly generated carry-in value.
摘要:
A method and apparatus for adding and multiplying floating-point operands such that a fixed-size mantissa result is produced. In accordance with the present addition method, the mantissa of a first floating-point operand is shifted in accordance with relative operand exponent information. Next, the first operand mantissa is added to the second operand mantissa. The addition step includes replacing a least significant non-overlapped portion of the first operand mantissa with a randomly-generated carry-in bit. In accordance with the multiplication method, a partial product array is generated from a pair of floating-point operand mantissas. Next, prior to compressing the partial product array into a compressed mantissa result, a lower-order bit portion of the partial product array is replaced with a randomly generated carry-in value.
摘要:
A circuit for generating control signals used in a microprocessor has a storage array, such as a read-only memory (ROM) array, which contains a plurality of predefined logic patterns. An entry of the ROM array is selected, such as by the use of an address decoder, to choose a specific pattern, and the specific pattern is then modified based on a dynamic signal to generate an output control signal. The microprocessor may further predecode a base instruction using operation and operand source bits to yield a predecoded instruction having an address field whose value corresponds to the specific pattern. The dynamic signal can be based on whether an operand should be forwarded from a microprocessor component, and the specific pattern is then equivalent to a value for control signals required to execute an instruction when assuming that the operand should not be forwarded. Special control states can also be implemented, such as stall, halt, or scan data, through the use of particular code points in the ROM.
摘要:
A superscalar computer architecture for executing instructions out-of-order, comprising a multiplicity of execution units, a plurality of registers, and a register renaming circuit which generates a list of tags corresponding to specific registers that are not in use during loading of a given instruction. A table is constructed having one bit for each register per instruction in flight. The entries in the table may be combined in a logical OR fashion to create a vector that identifies which registers are in use by instructions that are in flight. Validity bits can also be generated to indicate validity of the generated tags, wherein a generated tag is invalid only if an insufficient number of registers are available during loading of the given instruction. The execution units are preferably pipelined.