System for DMA data reception capable of confirming the content of a received data even if the received data is less than a preset length
AssigneeCanon Kabushiki Kaisha
InventorTakeaki Nakano
Life of this patent
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Abstract
There are provided a reception apparatus using direct memory access (DMA), a reception method and a memory medium, allowing one to confirm the content of the received data in the DMA data reception, even when the received data are shorter than a preset data length. In a DMA reception apparatus capable of making a request for an interruption to the MPU 1 in response to the reception of data of y bytes from the host computer, there is also made a setting of x bytes in addition to the setting of y bytes, in order to confirm the data content when the length of the data transmitted from the host computer is less than y bytes, and a request for interruption is made upon reception of data of x bytes from the host computer.
Claims25
A data reception apparatus comprising:
- a receiver arranged to receive, from a host computer, data for printing by direct memory access (DMA) reception;
- a data transfer unit that transfers the received data to a preset address of a random access memory;
- a reference data length setter which sets first and second reference data lengths, the second reference data length being shorter than the first reference data length;
- a first-interruption requester that makes an interruption request to a microprocessor unit (MPU) upon reception of data of the first reference data length set by said setter;
- a second-interruption requester that makes an interruption request to the microprocessor unit upon reception of data of the second reference data length set by said setter;
- and
- a discriminator that discriminates the received data.
A data reception method comprising the steps of:
- setting a first reference data length;
- setting a second reference data length shorter than the first reference data length;
- making an interruption request to a microprocessor unit (MPU) upon DMA reception of data for printing having the first reference data length;
- and
- making an interruption request to the microprocessor unit upon reception of data of the second reference data length.
A data reception program product including computer executable instructions for performing the steps of:
- setting a first reference data length;
- setting a second reference data length;
- making an interruption request to a microprocessor unit (MPU) upon DMA reception of data for printing having the first reference data length;
- and
- making an interruption request to the microprocessor unit upon the reception of data of the second reference data length.
A computer-readable memory medium that stores a data reception program, wherein the program comprises the steps of:
- setting a first reference data length;
- setting a second reference data length shorter than the first reference data length;
- making an interruption request to a microprocessor unit (MPU) upon DMA reception of data for printing having the first reference data length;
- and
- making an interruption request to the microprocessor unit upon reception of data of the second reference data length.
A system comprising a host computer and a data reception apparatus, wherein said data reception apparatus comprises:
- a receiver arranged to receive, from said host computer, data for printing by direct memory access (DMA) reception;
- a data transfer unit that transfers the received data to a preset address of a random access memory;
- a reference data length setter which sets first and second reference data lengths, the second reference data length being shorter than the first reference data length;
- a first-interruption requester that makes an interruption request to a microprocessor unit (MPU) upon reception of data of the first reference data length set by said setter;
- a second-interruption requester that makes an interruption request to the microprocessor unit upon reception of data of the second reference data length set by said setter;
- and
- a discriminator that discriminates the received data.
Dependencies are inferred from the claim text.