JPS63149753A - Data processor - Google Patents

Abstract

PURPOSE:To smoothly execute a series of input operation by providing a data processor with a pointer whose contents are updated at every ending of processing of each unit in a processing process up to the reception of transfer data. CONSTITUTION:An exclusive flag (IBF flag) is formed in a CPU 11 so as to recognize the presence of effective data in an input buffer 13, the pointer 19 is used as a counter, and when the IBF flag is turned on, the pointer 19 is reset to '00' to be started. After completing the reading of data from the input buffer 13, the pointer 19 is turned to '01', and at the time of completing the writing of data in a buffer 17, the pointer 19 is updated to '10', and at the time of ending the output of an acknowledge signal (ACK), the pointer 19 is turned to '11'. When the IBF flag is turned on by receiving new data in the buffer 13 again, the pointer 19 is cleared to '00'. Since a completed state in a data input sequence can be surely stored in hardware, smooth data input operation can be attained without especially applying a load onto software.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data processing device, and more particularly to a data processing device such as a printer that is coupled to a data supply source such as a host device and processes received supplied data. It is.

[Prior Art] Many data processing devices that are connected to a host device and transmit data in parallel are often used whose transmission control procedures are based on the Centronics standard. In this case, the printer side receives a strobe signal from the host device and captures the data transmitted in parallel (parallel data), and the printer side receives the strobe signal from the host device until the data capture operation is completed. Sends a busy signal to inform the other party that work is in progress. When the data capture is completed, an acknowledge signal is returned to the host device to notify it.

[Problems to be solved by the invention] Here, in the conventional data processing device, after data input,
Since the operation of returning the acknowledge signal was managed by software, if the CPU installed on the printer side accepts an interrupt midway through, executes the interrupt sequence, and then returns to the parallel data input sequence, the interrupt operation will be delayed. If you do not correctly recognize whether the parallel data input you were currently performing has been completed, or whether it is incomplete and you will have to input the previous data manually after the interrupt operation is completed, data may be missed or the same data may be lost. Problems such as double data import occurred.

[Means for Solving the Problem] The present invention solves the problem, and when data transfer processing such as sending of an acknowledge signal is managed manually or by software, data is inputted with interruptions etc. To provide a data processing device that can smoothly perform a series of input operations without overlooking the state of data manpower or placing a burden on the software by simply managing the software even when continuing work. purpose.

Therefore, the present invention includes a receiving means for receiving transferred data from a data supply source, a data processing means for taking in and processing the received data, and notifying the data supply source of the completion of the processing after the processing. In the process of receiving or notifying the transferred data! It is characterized by comprising a pointer whose contents are updated every time a unit of processing is completed.

[Operation] That is, according to the present invention, since the progress of the processing process can be monitored by referring to the pointer, data processing can be facilitated according to the monitoring. Further, if the pointer is configured with hardware, there is no need to place a burden on the software for executing the processing process.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration example of a data transfer system including a data processing device according to an embodiment of the present invention, and shows a data transfer system that performs signal transmission in accordance with the Centronics standard.

Here, 1 is a host device as a data supply source,
Various configurations can be used, such as a personal computer, a word processor, an image reading device, etc. Reference numeral 10 indicates a printer as a data processing device that receives image data from the host device 1 and performs output processing.

In the printer IO, 11 is a CPU that controls each part according to the processing procedure etc. described later in FIG. 3, and 12 is a C.
This ROM stores programs and fixed data corresponding to processing procedures executed by the PUII.

13 is a manual buffer that receives, for example, 8-bit parallel data DATA transferred from the host device 1 side, and in this example, in order for the CPIII to recognize whether there is valid data in the input buffer 13, a dedicated flag (hereinafter 1
11F flag) is provided.

14 is a printer mechanism, and CPIJII transfers the image data received in the manual buffer 13 via the buffer 17, and obtains a recorded output of the data accordingly.

Reference numeral 19 denotes a pointer, which is used to indicate the position of the sequence being executed when the processing procedure described later with reference to FIG. 3 is executed.

FIG. 2 shows an overview of Centronics-compliant control signals exchanged between the host device 1 and the printer IO. First, the host device 1 sends valid data DAT on the data line.
When A is placed, a strobe signal STB is sent to the printer 10 side.
is sent to notify that there is valid data. When the printer 10 receives this strobe signal STB, it starts an operation for manual data input, but in order to prohibit new data transfer from the host device 1 side until this data input operation is completed, it is Busy signal B indicating that
Send tlSY. When the printer 10 side completes the data input operation, it releases the busy signal BUSY indicating that the work is in progress, and returns an acknowledge signal AC to the host device zl side to notify the host device 1 side that data reception is complete. . Through the above process, the printer l
An operation is performed in which O takes in one parallel data.

Now, considering the manual operation on the printer IO side, first, when the printer 10 detects the strobe signal STB, it uses this as a trigger to raise the busy signal 811SY. At this time, since it would be inconvenient if there is a time delay between receiving the strobe signal STB and outputting the busy signal BIISY, this operation is normally performed by hardware made up of logic circuits, and when the strobe signal STB is received, it is automatically performed. A busy signal BuSY is returned automatically.

Furthermore, on the printer IO side, data is latched into the manual buffer 13 using the strobe signal STB as a trigger.

The CPU II, which controls each part of the printer IO, reads this latched data and writes this data, for example, onto the buffer 17 developed on the internal RAM, thereby completing the data capture process.

On the printer IO side, when data is latched into the input buffer 13, the IOF is provided so that the CPU II recognizes that there is valid data in the manual buffer 13.
The flag is monitored, and when the IBF flag is on, it is determined that there is valid data and data processing is performed. Conversely, when the IBF flag is off, it waits for the IBF flag to turn on. In this example, a series of input operations includes operations in which the CPIII reads data from the manual buffer 13 and writes previous data onto the internal buffer 17.

Next, when the printer 10 completes a series of manual data operations, it sends an acknowledge signal AC to notify the host device 1 of this fact, and also releases the busy signal n1tsY indicating that the printer is working. When returning the acknowledge signal ^C to the host device 1, in this example, cputt is configured to generate the acknowledge signal AC by itself after completing the data input operation.

FIG. 3(A) shows an example of a data manual processing procedure for performing such an operation. That is, in step S1 I
After waiting for the BF flag to turn on, at the time it turns on, the 8-bit data developed on the input buffer 13 is read in step S3, and then written to the buffer 17 in step S5. , and outputs an acknowledge signal AC in step S4.

Next, the processing at the time of an interrupt according to this example will be described. Third
Figures (B) and (C) respectively show processing flows when an interrupt (sequence A) occurs before writing to the buffer 17 and an interrupt (sequence B) occurs after writing. The binary value shown indicates the contents of pointer 19.

In this example, pointer 19 is used as a counter, and step 5
When the IBF flag 1 turns on, it is reset to "00°" and activated. Then, when the reading from the power buffer 13 in step S3 is completed, the pointer 19 becomes '01', and the buffer 19 When writing is completed, it is updated to "IO". Then, when the output of the acknowledge signal AC in step S5 is completed, the output becomes 11°, new data is received in the buffer 13 again, and the IBF flag is turned on, “0”.
Cleared to 0".

Here, this pointer 19 is not directly written by CPt1ll, but is automatically incremented and cleared each time (:PUll completes one operation of 5INS7, and this pointer 19 is automatically incremented and cleared, for example, by cputt and each part. This can be easily performed in connection with signal wiring or signal output.In this example, the following processing is performed in connection with interrupt processing.

Here, consider a case where the CPU II accepts an interrupt during a data input operation. That is, as shown in FIG. 3(B), if an interrupt occurs during the read operation from the manual buffer 13 in step S3, the CPt1ll allows the interrupt after the operation in step S3 is completed and jumps to interrupt sequence A. . When this interrupt sequence A is completed, the data manual procedure will be returned again, but here (:P!Jll reads the value of pointer 19. At this time, pointer 19 is the value before jumping to interrupt sequence A. Since the reading operation of the large power buffer 13 in step S3 has been completed, "Ol" is shown. However, the writing to the buffer 17 has not been completed, and the data of the input buffer 13 has been read internally. Since this is not the case, the read operation of the manual buffer 13 is executed again (step S3'), and after writing the data into the buffer 17 (step S5), an acknowledge signal is output to C (step S7). .

Next, as shown in FIG. 3(C), consider the case where an interrupt occurs during the write operation to the buffer 17 in step S5. At this time, after the CPU II finishes writing data to the buffer 17, it allows interrupts and jumps to the interrupt sequence. At this time, the pointer 19 has been incremented to "lO". Then, when interrupt sequence B ends and returns to the main flow,
When the value of pointer 19 is checked, it is 10'', so cputl knows that the data input operation has been completed, and the acknowledge signal AC in step S7 is
The output operation will be performed as follows.

As described above, according to this example, even if an interrupt occurs during a data input operation by the printer 10 and the manual operation is temporarily interrupted, the hardware will not be able to determine how far in the data input sequence has been completed after the interrupt operation ends. Since the data can be clearly stored in the software, there is no particular burden on the software, and smooth data input operations are possible without missing data or double reading.

Note that although a system in which a host device as a data supply source and a printer as a data processing device are combined is described above, the present invention is not limited to such a configuration; Of course, the present invention can be applied very effectively and easily to various types of data processing apparatuses that process this data.

[Results of the Invention] As explained above, according to the present invention, the position of the sequence executed by the data processing device can be recognized by the hardware, so the transfer processing such as inputting data or sending out an acknowledge signal can be performed by software. When managing data manually, even if you continue to input data with interruptions, etc., you can manage the data by simply managing the software, without overlooking the state of human data, or without putting a burden on the software. A data processing device that can operate smoothly can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a configuration example of a data transfer system including a data processing device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration example of a data transfer system including a data processing device according to an embodiment of the present invention. FIG. Timing Chart Showing Outline of Various Signals FIGS. 3A to 3C are flowcharts showing an example of a data input processing procedure performed by the data processing apparatus shown in FIG. 1...Host device, IO...Printer, 11...-cpo. 12...ROM. 13...Input buffer, 14...Printer mechanism, 17...Buffer, 19...Pointer, IBF...Flag, DATA...Parallel data, STB...Strobe signal, BUSY... Busy signal, AC...acknowledge signal. Figure 2

Claims (2)

[Claims] (1) receiving means for receiving transferred data from a data supply source; data processing means for taking in and processing the received data and notifying the data supply source of the completion of processing after the processing; A data processing device comprising: a pointer whose contents are updated every time one unit of processing is completed in a processing process from receiving transfer data to the notification. (2) In the data processing device according to claim 1, the pointer is updated at least every time the process related to receiving the transfer data ends and the process related to the capture of the data ends, and the processing means A data processing apparatus, characterized in that the content of the pointer is referred to in connection with processing, and if the processing related to the fetching has not been completed when the interrupt processing ends, the fetching processing is executed.