JP2000141782A - Recorder and data transfer method therfor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance data processing efficiency by eliminating overlap of the processing for generating a data to be recorded and the processing for transferring the recording data. SOLUTION: The recorder comprises DRAMs 8, 16 connected with independent buses while having regions 9, 17 for storing a data received by a receiving circuit 1, regions 10, 18 for storing the receiving data frozen through a freezing circuit 2, and regions 11, 19 for storing the processing results of an HV conversion circuit 3, and a DMA controller 15 for transferring the data by DMA between each DRAM 8, 16 and the receiving circuit 1, the freezing circuit 2, the HV conversion circuit 3, and a transfer circuit 4, wherein the DMA controller 15 executes DMA transfer for writing the data to any one of the DRAM 8 or 16 and DMA transfer for reading the data from the other DRAM alternately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording apparatus for receiving data from an external device and recording the data on a recording medium, and a data transfer method in the recording apparatus.

[0002]

2. Description of the Related Art Conventionally, recording is performed by receiving data from an external device, decompressing and HV-converting the data (a process of converting and aligning data in accordance with the arrangement of recording elements (nozzles and the like) of a recording head) and recording. Devices are known. Such a recording apparatus includes a large-capacity DRAM for storing received data, processed data, and the like.
DMA transfer of data under the control of AC, etc.
Data is read from the RAM by the DMA.

[0003]

However, in such a configuration, during recording, the HV converted data stored in the DRAM is frequently transferred to the recording head by DMA. Therefore, other DMAs accessing the DRAM, for example, storing received data in the DRAM, DRA
DMA processing for reading out and decompressing the received data stored in M or further storing the result of HV conversion in DRAM again is awaited. That is, during recording, the time T given to the other DMAs described above is expressed by the following equation.

T = (one scan recording time)-(DMA transfer time required for one scan recording) Here, if the time given to the other DMA is sufficient, the recording performed by scanning the carriage ends. When the carriage decelerates and stops, the HV-converted data for one scan recorded in the next one-scan recording scan is converted to DRA.
M must be stored in M. If so, the recording scan by the next one scan can be started immediately.

[0005] However, in recent years, the performance of a recording apparatus has been increased and the recording of a high-definition image has become possible. Therefore, while the recording time of one scan is reduced by such high speed, the amount of data to be recorded is increased by the high definition of a recorded image, and the HV conversion required for the recording of one scan is completed. The time for DMA transfer of data is increasing. That is, in the above equation, (one scan recording time) is shortened, and (DMA transfer time required for one scan recording) is becoming longer, and as a result, the time T is becoming shorter.

When the time T decreases in this manner, the recording by one scan of the carriage is completed, and when the carriage is decelerated and stopped, the HV converted data for the next one scan is not prepared in the DRAM. Occurs.
In this case, there is a waiting time between the suspension of the printing operation by the carriage scanning and the completion of the printing data for the next one scan. Therefore, no matter how much the moving speed of the carriage is increased or the number of nozzles of the head is increased, there is a problem that the throughput of the recording process does not increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional example, and separately provides a memory having a memory area for storing received data and processing data and a memory area for storing data used for recording. A recording apparatus which increases processing efficiency of data by eliminating a process of creating data to be recorded and a process of transferring the recording data by switching a DMA transfer route between the memories and the recording apparatus; An object of the present invention is to provide a data transfer method in a device.

[0008]

In order to achieve the above object, a recording apparatus according to the present invention has the following arrangement. That is, each has at least a reception data storage area for storing reception data by the reception means, and a data storage area for storing the result of processing the reception data by the data processing means.
And a second memory, recording means for recording an image based on data from the data storage area of the first or second memory, each of the first and second memories, the receiving means, and the processing means DMA means for performing data transfer by DMA between the independent means and the recording means via each of the independent buses; and the first and the second means by the DMA means in response to reception of a predetermined amount of data by the receiving means. D for storing data in one of the second memories
A control means for alternately executing the MA and the DMA for reading data from the other memory and transferring the data to the recording means is provided.

In order to achieve the above object, a data transfer method in a recording apparatus according to the present invention includes the following steps. That is, each has at least a reception data storage area for storing reception data by the reception means, and a data storage area for storing the result of processing the reception data by the data processing means. And a second memory, a data transfer method in a recording apparatus for receiving and recording data sent from an external device by the receiving means, wherein the data is transferred to one of the first and second memories. A first DMA transfer step of executing at least a DMA transfer for storing received data; a second DMA transfer step of reading data from the other of the first and second memories and performing a DMA transfer; In response to receiving a predetermined amount of data,
A control step of alternately executing the first DMA transfer step and the second DMA transfer step.

[0010]

[First Embodiment] FIG. 1 is a block diagram showing a configuration of an ink jet recording apparatus according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a receiving circuit which receives print data sent from a personal computer or the like. A decompression circuit 2 decompresses (expands) the compressed data. Reference numeral 3 denotes an HV conversion circuit which converts data sent in raster order as shown in FIG. 2 into data rearranged in the column direction to be transferred to the inkjet head 5 and recorded. A transfer circuit 4 transfers the HV-converted data to the inkjet head 5. Reference numeral 5 denotes an ink jet head that performs recording by discharging ink droplets. A data counting circuit 13 counts the number of received rasters. The bus 14 connects the reception circuit 1, the decompression circuit 2, the HV conversion circuit 3, and the DMA controller 15 with the DRAM switching circuit. This DMA controller 15
DMA transfer between the AM 8 and the DRAM 16 can be performed independently and simultaneously. That is, the DRAM 8
While data is stored in the DRAM 16, processed data can be read from the DRAM 16 by DMA and transmitted to the transfer circuit 4. Conversely, while data is stored in the DRAM M16, processed data can be read from the DRAM 8 by DMA. The data can be transmitted to the transfer circuit 4.

Reference numeral 8 denotes a DRAM, which includes a reception data area 9, a decompressed data area 10, and an HV converted data area 11, which are data areas existing at different addresses inside the DRAM 8, respectively. The reception data area 9 is a storage area for storing data received by the reception circuit 1. The decompressed data area 10 stores data decompressed by the decompression circuit. The HV-converted data area 11 stores data subjected to HV conversion by the HV conversion circuit 3 in accordance with the arrangement of the nozzles of the inkjet head 5.

A DRAM 16 is the same DRAM as the DRAM 8,
Received data area 17, decompressed data area 18, and H
A V-converted data area 19 is provided, each of which exists at a different address inside the DRAM 16 and stores data processed by a corresponding circuit similarly to the DRAM 8.

In the DMA1, the receiving circuit 1 converts the received data into a DR.
DMA for writing to AM8 or DRAM9,
DMA2 is a DMA for reading the received data in the DRAM 8 or the DRAM 9 by the decompression circuit 2, DMA3 is a DMA for writing the decompressed data to the DRAM 8 or the DRAM 9, and DMA4 is a DRAM 8 or the DRA.
This is a DMA for the HV conversion circuit 3 to read out the decompressed data in M9.
The DMA 6 is a DMA for writing to the RAM 8 or the DRAM 9, and the DMA 6 is a DMA for the transfer circuit 4 to read HV converted data in the DRAM 8 or the DRAM 9. Each of these circuits is a DRAM 8 or DRAM
When the DMA controller 9 is accessed by DMA, a DMA request is issued to the DMA controller 15 with a DRAM switching circuit. DM
The A controller 15 returns an ACK signal and approves the access by the DMA unless the memory is being used by another DMA or at the same time a request occurs. If not, make the user wait for access. The operation of the DMA controller with DRAM switching circuit 15 will be described later in detail.

FIG. 3 is a view for explaining the scanning direction of the ink jet head 5. Here, the plurality of nozzles of the inkjet head are arranged in the scanning direction (main scanning direction) of the head 5.
Are arranged in a direction (sub-scanning direction) substantially orthogonal to
In a single scan (scan), data having a width corresponding to the length of the plurality of nozzle rows is recorded.

FIG. 4 is a diagram showing a data flow when the receiving circuit 1 is receiving data of the first scan. In FIG. 4, each of dotted lines 400 to 404 indicates a transfer by DMA.

When the receiving circuit 1 receives print data from an external device (host computer), the DMA 1 is started, and as shown by 400, the received data is stored in the received data area 9 of the DRAM 8 by DMA. At the same time, the data counting circuit 13 counts the number of rasters of the received data.
The DMAC 15 with the switching circuit is instructed to switch the DRAM to which the received data is transferred. Decompression circuit 2
DMA2 is received when the data of the first scan is completely received.
The received data is read from the received data area 9 by the DMA indicated by 401 and decompressed. DMA3 and DMA402 decompress the data.
In the decompressed data area 10. Next, the HV conversion circuit 3 is started, and the decompressed data is read from the decompressed data area 10 by the DMAs 403 and DMA4.
The data is converted into data corresponding to the nozzle arrangement of the inkjet head 5 and stored in the HV converted data area 11.

As described above, when it is detected by the data counting circuit 13 that data for one scan has been received, the data for the second scan is then sent to the DRAM 16 by the DMAC 15 with a DRAM switching circuit. It is memorized. FIG. 5 shows this state.

The operation of the second scan is basically the same as the operation of the first scan, except that the DRAM for storing the data to be processed is changed from the DRAM 8 to the DRAM 16.
The difference is that it has been changed. That is, the receiving circuit 1
Receives print data from an external device (host computer), DMA1 is activated, and as shown by 500,
The received data is stored in the received data area 17 of the DRAM 16 by the DMA. At the same time, the data counting circuit 13
Counts the number of rasters of the received data, and when data for one scan is received, DM with a DRAM switching circuit
The AC 15 is instructed to switch the DRAM to which the received data is transferred from the DRAM 16 to the DRAM 8 this time. When the reception of the data of the second scan is completed, the decompression circuit 2 reads the reception data from the reception data area 17 by the DMAs indicated by DMA2 and 501, and decompresses the read reception data. DM decompressed data
The data is stored in the decompressed data area 18 by A3 and the DMA 502. Next, the HV conversion circuit 3 is activated and the DMA 50
(3) The decompressed data is read from the decompressed data area 18 by the DMA 4, converted into data corresponding to the nozzle arrangement of the inkjet head 5, and stored in the HV converted data area 19.

Further, during data processing such as reception and decompression of data of the second scan and HV conversion, data of the first scan already received and processed and stored in the HV converted data area 11 of the DRAM 8 are , DMA505,
The data is DMA-transferred to the transfer circuit 4 by the DMA 6 and sent to the inkjet head 5 via the transfer circuit 4 for recording.

As described above, in the first embodiment, a DRAM that receives and processes data from an external device is different from a DRAM that reads HV converted data during a recording operation. Therefore, conventionally, the time given to the DMA for preparing data for the next one scan during recording is limited to (recording time for one scan)-(time of DMA 6 required for recording for one scan). On the other hand, according to the first embodiment, the DMA 6 required to transfer the HV-converted data to the head 5 does not affect the reception and data processing of the next one scan. There is an effect that substantially all of the recording time for one scan can be used to prepare data for the next one scan.

FIG. 6 is a flowchart showing a data receiving process in the ink jet recording apparatus of the present embodiment. A program for executing this process is stored in a program memory (1012 (FIG. 12)) of a control unit (1000 (FIG. 12)) of the ink jet recording unit described later, and a flag (FLAG) used in this process is set. RAM
It is provided in.

This process is started when the power of the apparatus is turned on. First, in step S1, the flag (FLAG) is set to "0".
Then, in step S2, it is checked whether or not data has been received from an external device. When data is received, the data is received by the data receiving circuit 1, and in step S3, whether or not the flag (FLAG) is "0" is determined. View. If "0", the process proceeds to step S4, and the received data is DMA-transferred and stored in the reception data area 9 of the DRAM 8 (DMA400 in FIG. 4). On the other hand, the value of FLAG is “0”
If not, the process proceeds to step S5, where the received data is DMA-transferred and stored in the reception data area 17 of the DRAM 16 (DMA 500 in FIG. 5). When the received data is stored in step S4 or step S5 in this manner, the process proceeds to step S6, where it is checked whether data for one scan has been received.
If not, the flow returns to step S2 to execute the above-described processing.

When data for one scan is received in step S6, the flow advances to step S7 to check the current state of the flag. If the value of FLAG is "0", the flow advances to step S8 to receive data from the reception data area 9 of the DRAM 8. D
The data is read out by the MA (DMA 401) and decompressed by the decompression circuit 2 and the result is decompressed by the DMA in the data area 10
(DMA 402). Further, the decompressed data is sent to the HV conversion circuit 3 by DMA (DMA4
03) HV conversion is performed so as to conform to the arrangement of the nozzles of the inkjet head 5 according to the arrangement, and the result is DMA-transferred (DMA404) to the HV-converted data area 11 and stored.

On the other hand, in step S6, the value of the flag is "0".
If not, the flow advances to step S9 to transfer the reception data from the reception data area 17 of the DRAM 16 to the DMA (DMA 501).
And decompresses it by the decompression circuit 2 and stores the result in the decompressed data area 18 by DMA (DMA5
02). Further, the decompressed data is converted into H
The data is sent to the V conversion circuit 3 (DMA 503) and subjected to HV conversion to form an array corresponding to the arrangement of the nozzles of the inkjet head 5, and the result is DMA transferred (DMA 504) to the HV converted data area 19 and stored.

When the process of step S8 or S9 is completed, the process proceeds to step S10, in which the value of the flag is inverted and stored, and it is determined in step S11 whether or not the data of the next scan is received. Thus, if there is received data for the next scan, the process returns to step S2 to execute the above-described processing.

In this way, the storage and conversion processing of the received data is executed using the DRAMs 8 or 16 alternately.

FIG. 7 is a flowchart showing a printing process which can be executed in parallel with the data receiving process of FIG. 6, and this process is performed at a print timing when, for example, the carriage on which the inkjet head 5 is mounted reaches the recording position. It is activated by

First, in step S21, it is checked whether or not the value of the flag is "0".
Proceed to. In this case, since the DRMA 8 is used as a storage and conversion area for the received data,
It is checked whether data to be printed is stored in the V-converted data area 19. If the data is stored, the process proceeds to step S23, and the data is DMA-transferred from the HV-converted data area 19 to the transfer circuit 4.

On the other hand, if the value of the flag is not "0" in step S21, the process proceeds to step S24. in this case,
Since the DRMA 16 is used as an area for storing and converting received data, it is checked whether data to be printed is stored in the HV converted data area 11 of the DRAM 8.
If the data is stored, the process proceeds to step S25, and the data is DMA-transferred from the HV-converted data area 11 to the transfer circuit 4 (DMA 505 in FIG. 5).

[Embodiment 2] FIG. 8 is a block diagram showing the configuration of an ink jet recording apparatus according to Embodiment 2 of the present invention. Portions common to those in FIG. Is omitted.

In the figure, reference numeral 21 denotes a switching selection circuit.
DRA for each scan depending on the amount of data for the scan
Select whether to switch M8, M16 or not.

In general, an ink jet recording apparatus can correspond to various recording modes and paper sizes (recording ranges). Therefore, the data amount corresponding to one scan increases or decreases according to various conditions such as the print mode and the print size. For example, when recording on A4 paper, A3
The amount of data for one scan is greater when recording on a sheet of paper, and the amount of data for one scan is greater when recording a photographic image in color than when recording text in monochrome.

In general, an ink jet recording apparatus is required to have a DRAM having a capacity capable of storing a maximum of one scan of data in any recording mode or recording range due to its configuration. For this reason, many high-definition image data and large-format ink jet recording apparatuses use two or more DRAMs. In such an ink jet recording apparatus, when the data amount for one scan is small, for example, when the recording paper size is A4, the DRAM used for each scan is switched as in the first embodiment. This makes it possible to improve the use efficiency of the DMA.

FIG. 9 shows a second embodiment of the present invention.
The DMA transfer during the recording operation when there is a large amount of data for one scan is indicated by a dotted line.

Here, the DRAMs 8 and 16 are used alternately. For example, when data is received, the reception data areas 9 and 16 are used.
17 are used alternately to store the data received by the receiving circuit 1. Decompressed data area 10, 1
8, the HV converted data areas 11 and 19 are used alternately, and during the recording operation, the HV converted data areas 11 and 1 are used.
The print data is alternately read from 9 and transferred to the ink jet head 5 by the transfer circuit 4 for recording.

In this manner, a plurality of relatively small-capacity D
The RAM can be treated as if it were one large-capacity DRAM.

On the other hand, FIG. 10 is a view for explaining the DMA transfer when the data for one scan is small in the second embodiment. Here, the received data is stored in the DRAM 8, and the converted data is
The data is read by the MA and output to the head 5 by the transfer circuit 4.

Next, the configuration of the ink jet recording apparatus of the present embodiment will be described. In the present embodiment,
Although the case of an ink jet recording apparatus will be described, the present invention is not limited to this, and it is needless to say that the present invention can be applied to, for example, a thermal printer or an electrophotographic printer.

FIG. 11 is a schematic view showing the configuration of a recording section of an ink jet recording apparatus according to an embodiment of the present invention.
2 is a block diagram showing the configuration of the ink jet recording apparatus.

In FIG. 11, reference numeral 205 denotes a head cartridge in which the recording head H and an ink tank serving as an ink supply source are integrated. The head cartridge (corresponding to the above-described head 5) is fixed on a carriage 206 by a pressing member 202. The carriage 206 reciprocates in a longitudinal direction along a shaft 211 to perform recording. The ink ejected from the recording head H reaches the recording medium 209 whose recording surface is regulated by the platen 210 at a minute interval from the recording head H, and forms an image.

The recording head H has a flexible cable 207
The ejection (recording) signal corresponding to the image data is supplied from the transfer circuit 4 via the electrodes coupled to the above.
One or more (two in the illustrated example) print heads H can be provided according to the color of the image to be printed. 2
A carriage motor 08 causes the carriage 206 to scan back and forth along the shaft 211 by its rotation. 20
Reference numeral 3 denotes a wire which is stretched between a pulley provided on the rotation shaft of the carriage motor 208 and a pulley 212 provided at a position facing the scanning range, and one end of which is fixed to the carriage 208, Carriage motor 20
8 is transmitted to the carriage 206. Also,
Reference numeral 201 denotes a paper feed motor (feed motor) which rotates the platen roller 210 via a gear to rotate the recording medium 20.
9 is conveyed. 204 is an HP (home position) for detecting that the carriage 206 has reached the home position.
It is a sensor. At this home position, the head cartridge 205 can be replaced.

FIG. 12 is a block diagram showing the structure of the ink jet recording apparatus.

In the figure, reference numeral 1000 denotes a control unit, which comprises a circuit as shown in FIG. 1 or FIG. 1001
Denotes a head driver, which drives the recording head 5 based on the data transferred by the transfer circuit 4. 1002,1
Reference numeral 003 denotes a motor driver, which rotationally drives the corresponding carriage motor 208 and feed motor 201, respectively. Reference numeral 1011 denotes a CPU such as a microprocessor, and 1012, a ROM (program memory) storing a control program executed by the CPU 1011 and 1013, when the CPU 1011 operates.
This is a RAM used as a work area or the like.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but can be applied to a single device (for example, a copier, a facsimile). Device).

Another object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus.
Or MPU) reads and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) Performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, The case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing.

As described above, according to the first embodiment, two or more DRAMs are provided, and a DMA transfer for reading data to be printed and a D / A for reception and data conversion are performed.
By adopting a configuration in which MA transfer is performed independently, high-speed and high-quality image recording can be performed in a recording apparatus that receives and records a large amount of image data.

According to the second embodiment, the data can be received and recorded at a high speed by changing the method of using the DRAM according to the amount of data.

[0053]

As described above, according to the present invention, a memory having a memory area for storing received data and data for processing and a memory area for storing data used for recording are separately provided. D between these memories
By switching the MA transfer route, data processing efficiency can be increased by eliminating the overlap between the process of creating data to be recorded and the process of transferring the recorded data.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a main part of an inkjet recording apparatus according to a first embodiment.

FIG. 2 is a diagram illustrating raster data sent to the inkjet recording apparatus according to the embodiment.

FIG. 3 is a diagram illustrating head scanning during printing in the inkjet printing apparatus of the present embodiment.

FIG. 4 is a diagram illustrating a flow of data at the time of data reception in the inkjet recording apparatus according to the first embodiment.

FIG. 5 is a diagram illustrating the flow of data during recording and data reception in the inkjet recording apparatus according to the first embodiment.

FIG. 6 is a flowchart illustrating a process at the time of data reception in the inkjet recording apparatus of the present embodiment.

FIG. 7 is a flowchart for explaining processing at the time of recording in the ink jet recording apparatus of the present embodiment.

FIG. 8 is a block diagram illustrating a configuration of a main part of an inkjet recording apparatus according to a second embodiment.

FIG. 9 is a diagram illustrating a flow of data when receiving data in the inkjet recording apparatus according to the second embodiment.

FIG. 10 is a diagram illustrating the flow of data during recording and data reception in the inkjet recording apparatus according to the second embodiment.

FIG. 11 is a schematic view of a recording unit of the ink jet recording apparatus according to the embodiment.

FIG. 12 is a block diagram illustrating a configuration of an inkjet recording apparatus according to the present embodiment.

Claims (12)

[Claims] At least one receiving data storage area for storing received data by a receiving means and a data storing area for storing a result of processing the received data by a data processing means are respectively connected to independent buses. First and second memories, recording means for recording an image based on data from the data storage area of the first or second memory, each of the first and second memories and the receiving means, D for performing data transfer by DMA between the processing means and the recording means via each of the independent buses
MA means; DMA for storing data in one of the first and second memories by the DMA means in response to reception of a predetermined amount of data by the receiving means; and reading data from the other memory. D for transferring to the recording means
And a control means for executing the MA alternately. 2. The printing apparatus according to claim 1, wherein the predetermined data amount is a data amount corresponding to data for one scan. 3. The recording apparatus according to claim 1, wherein the control unit includes a measuring unit that measures an amount of data received by the receiving unit. 4. The recording apparatus according to claim 1, wherein said data processing means expands the compressed received data. 5. The recording apparatus according to claim 1, wherein the data processing unit rearranges the image data into data according to an arrangement of recording elements in the recording unit. 6. The apparatus according to claim 1, further comprising selection means for causing said control means to select whether or not to switch DMA between said first and second memories for each of said predetermined data amount. The recording apparatus according to any one of claims 1 to 5, wherein 7. At least a reception data storage area for storing reception data by reception means, and a data storage area for storing a result of processing the reception data by data processing means, each being connected to independent buses. A data transfer method in a recording apparatus having a first and a second memory, and receiving and recording data sent from an external device by the receiving means, wherein the first and second memories are On the other hand, at least a first for executing a DMA transfer for storing at least received data.
A DMA transfer step; a second DMA transfer step for reading data from the other of the first and second memories and performing a DMA transfer; and a first DMA transfer step in response to reception of a predetermined amount of data by the receiving means. And a control step of alternately executing the second DMA transfer step and a second DMA transfer step. 8. The data transfer method according to claim 7, wherein the predetermined data amount is a data amount corresponding to data for one scan. 9. The data transfer method according to claim 7, wherein the control step includes a measurement step of measuring an amount of data received by the reception unit. 10. The data transfer method according to claim 7, wherein said data processing means expands the compressed received data. 11. The data transfer method according to claim 7, wherein said data processing means rearranges the image data into data according to the arrangement of recording elements in the recording means. 12. The control method according to claim 11, further comprising a selection step of selecting whether to switch the first and second DMA transfer steps alternately or not for each of the predetermined data amounts. 12. The data transfer method according to any one of 7 to 11.