Tag-based implementations enabling high speed data capture and transparent pre-fetch from a nor flash
AssigneesSTMicroelectronics (Grenoble 2) SAS, STMicroelectronics International N.V.
InventorsAnkur Behl, Gregory Poivre
Life of this patent
Estimating the term…
Abstract
Embodiments disclosed herein generally relate for efficiently retrieving boot code for a processor from serial NOR flash memory. When a boot code request is received, a request handler in data capture logic tags successive address read requests to indicate whether the requests indicate contiguous addresses in the NOR flash memory for the boot code. Different circuitry in the data capture logic operates on different mesochronous clock signals. One clock signal drives the capture of boot code from NOR flash, and the other controls synchronized tagging, storing, pre-fetching, and transmitting of the captured boot code data.
Claims20
A system comprising a controller operating on a controller clock signal and electrically coupled to a flash memory device through an input/output (I/O) socket and capable of receiving data from the flash memory device, the system comprising:
- a transmitter state module receiving the controller clock signal configured to generate a selective clock signal based on the controller clock signal and configured to provide the selective clock signal to the I/O socket, wherein passage of the selective clock signal through the I/O socket creates a feedback clock signal;
- and
- data capture logic configured to receive the feedback clock signal from the I/O socket and comprising one or more storage elements configured to capture data from the flash memory device according to the feedback clock signal.
A system comprising a controller operating on a controller clock signal and electrically coupled to a flash memory device through an input/output (I/O) socket and capable of receiving data from the flash memory device, the system comprising:
- a request handler configured to receive read requests from a processor and store tags corresponding to the read requests in a pack storage element, wherein the tags indicate whether each of the read requests are contiguous or non-contiguous;
- a transmission state module configured to generate a selective clock signal based on the controller clock signal and provide the selective clock signal to the I/O socket to generate a feedback clock signal;
- data capture logic configured to receive the feedback clock signal from the I/O socket and comprising one or more additional storage elements configured to capture data from the flash memory device according to the feedback clock signal;
- and
- a response handler configured to provide the processor with the data until a non-contiguous tag is received.
A system comprising a controller operating on a controller clock signal and electrically coupled to a flash memory device through an input/output (I/O) socket and capable of receiving data from the flash memory device, the system comprising:
- a request handler configured to receive read requests from a processor and store tags corresponding to the read requests in a pack storage element, wherein the tags indicate whether each of the read request are contiguous or non-contiguous;
- a transmission state module configured to generate a selective clock signal based on the controller clock signal and provide the selective clock signal to the I/O socket to generate a feedback clock signal, the transmission state module is also configured to generate synchronization tags for each of the read requests;
- data capture logic configured to receive the feedback clock signal from the I/O socket and comprising one or more additional storage elements configured to capture data from the flash memory device according to the feedback clock signal;
- a receiver state module configured to retrieve and store the data captured by the data capture logic in a data memory element according to the controller clock signal;
- and
- a response handler configured to provide the processor with the data until a non-contiguous tag is received.
Dependencies are inferred from the claim text.