Atmel Corporation

Frédéric Schumacher

Guillaume Pean

Renaud Tiennot

Franck Lunadier

A peripheral interface circuit and method is disclosed for dealing with round trip delay with serial memory. In some implementations, a finite state machine is configured to introduce a delay state prior to a read data state to absorb round trip delay associated with a memory read operation. A clock module is coupled to the finite state machine and configured to delay start of a pad return clock for the read operation until completion of the delay state. A first synchronous logic is coupled to receive the pad return clock and is configured to sample and hold data from a data bus during the read data state of the memory read operation based on the pad return clock. A second synchronous logic is coupled to receive a system clock and is configured to sample the held data based on the system clock.

Peripheral interface circuit for serial memory

A microcontroller includes a microprocessor, a serial flash memory interface, and input/output (I/O) terminals for coupling the serial flash memory interface to external serial flash memory. The microprocessor is operable to generate instruction frames that trigger respective commands to read data from specified addresses in the external serial flash memory. The serial flash memory interface receives and processes the instruction frames, obtains the data contained in the specified addresses in the external serial flash memory regardless of whether the specified addresses are sequential or non-sequential, and provides the data for use by the microprocessor.

Microcontroller with integrated interface enabling reading data randomly from serial flash memory

A memory controller is configured to receive read requests from a processor and return memory words from memory. The memory controller comprises an address comparator and a loop entry cache. The address comparator is configured to determine a difference between a previous read request address and a current read request address. The address comparator is also configured to determine whether the difference is positive and less than a certain address difference and, if so, indicate a limited backwards jump. The loop entry cache is configured to store a current memory word for the current read request address when the address comparator indicates a limited backwards jump.

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Trets, France

Frédéric Schumacher