Abstract: A processor has an external pin that can be asserted to lock in new clock ratio information dynamically. A state machine of the processor defines a stop grant state that is utilized to halt the internal clocking signal of the processor. A storage location, such as a register, is utilized to load new clock frequency information into the clock generator circuit of the processor. De-asserting the external pin of the processor causes the processor to resume normal operations, but at the newly set clock frequency.

Abstract: An apparatus to identify a storage device of a processor within a digital system is described. The processor includes a first storage device designed to generate a first signal when the first storage device contains a copy of a requested entry in a main storage device. The first signal is in a first state when the copy is of a first type and is in a second state when the copy is of a second type. A second storage device is included that is designed to generate a second signal when the second storage device contains the copy of the requested entry in the main storage device. The second signal is in the first state when the copy is of the first type and is in the second state when the copy is of the second type. The processor also includes a first logic device that generates a first indicator signal in response to receiving the first signal, and is coupled to the first storage device. The indicator signals are representative of the storage device that contains.

Abstract: A system includes a component (e.g., a processor) that includes a clock generator that generates an internal clock running at a frequency. A controller generates a clock frequency change indication and places the component into a low activity state (e.g., deep sleep, stop grant, or other state). The clock generator is reset by the clock frequency change indication to change the clock's frequency while the component is in the low activity state. Storage elements containing different values are selectable to set the clock frequency. The storage elements include fuse banks and input pins.

Abstract: Briefly, in accordance with one embodiment of the invention, a slew rate control circuit for a processor includes: a circuit configuration to produce a signal representing the speed of fabricated transistors; and a circuit configuration to adjust, based at least in part on the signal representing the speed of fabricated transistors, the amount of current produced by a pre-driver stage for an output buffer of the processor. Briefly, in accordance with another embodiment of the invention, an integrated circuit includes: a slew rate control circuit for a buffer including: a register capable of storing at least one binary digital signal, a pre-driver, and at least one pre-driver cell coupled to the pre-driver. The at least one pre-driver cell is coupled to the pre-driver and register so as to modify the amount of current produced by the pre-driver based, at least in part, on the at least one binary digital signal.

Abstract: A method and apparatus for the pipelining of data during direct memory accesses. The processor includes an external bus controller, which receives data transmitted across the external bus from an external device, and forwards the data onto the memory bus for transfer to the memory. Similarly, the bus controller receives data to be written to external device from the memory and transfers it across the external bus to the external device. The bus controller includes logic to detect burst transfers and word alignment to determine the minimum number of words that can be transferred across the memory bus while the data transfer from the external device is ongoing. Therefore, instead of waiting for the entire block of data to be received into the processor before transferring it to the memory, portions of the block transferred, for example, two words at a time, are transferred to the memory, while additional data is being received at the processor.