JPS60218939A - Controller of copying machine or the like - Google Patents

Abstract

PURPOSE:To increase the data transfer speed and the reprocessing speed when an error occurs by providing a clock generator for clocks to be supplied to each part and a clock monitor means at a primary data processing part and monitoring the clock state sent from the primary data processing part at the secondary data processing part. CONSTITUTION:If a data error is detected at a secondary data processing part 12, a CPU15 holds an error signal 39 at level H for a prescribed period of time. Thus the clocks transmitted via a clock transmission line 42 are interrupted while the signal 39 is kept at H. Then a timer 27 of a primary processing part 11 counts up the time to produce an interruption signal 44. Then a CPU14 starts the interruption processing with the signal 44 and prepares for retransmission of data of each prescribed unit which is transferred imediately before the start of said interruption processing. When a data error is detected at the part 11, a timer 33 of the part 12 counts up the time. Then an interruption is applied to the CPU15 by an interruption signal 45. In this case, the data is transmitted again from the part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device used in electronic equipment such as a copying machine.

[Prior art]

Many relatively advanced electronic devices such as copying machines use a CPU (
It is equipped with a central processing unit (central processing unit) to process various data. In general, data processing by a control device can be broadly classified into centralized processing type and distributed processing type. Here, the centralized processing type is a type in which a control device is configured with a single CPU, and all operations are controlled by this. Also, distributed processing type is
This is a type of electronic device that includes multiple CPUs and distributes data processing to each of the main functional units of the electronic device.

In recent years, distributed processing type control devices have become mainstream in high-performance electronic copying machines. This requires sophisticated control of major functional parts such as (i) ■Document feeder, ■Copying process control unit such as exposure and development, ■Paper feeder, and ■Collation device (soak). (ii) Distributed processing makes it easier to add various functions to the copying machine as an option.

However, in such a distributed processing type control device, data transfer between data processing sections each having a CPU as a core becomes a problem. Transfer formats for such devices include (i) a format in which data is transferred in parallel, and (11) a format in which data is transferred in series.

Among these, (1) in the parallel transfer type control device, (1) the number of cables connecting the data processing units increases, and the reliability of the connection decreases; Also, it becomes difficult to route the cables, making it impossible to freely arrange each data processing section. Furthermore, since the number of cables is large, the probability of receiving noise increases, and the reliability of circuit operation also decreases.

(ii) For the serial transfer type, ■control device is required.
There are two types: one is a synchronous type in which each data processing unit uses a common clock, and the other is an asynchronous type in which each data processing unit uses its own clock. Among these, the synchronous type uses a common clock and can increase the data transfer speed, but has the disadvantage of being susceptible to noise. For example, electronic copying machines use many noise generating sources such as chargers and motors. Therefore, there is a high risk that the clock will be disturbed by noise.
Errors are likely to occur during data transfer. Conventionally, as a measure for this purpose, the data transfer result was transmitted from the receiving side to the transmitting side every time a predetermined amount of data was transferred. However, if this method is adopted, if a large amount of data is transferred at one time, it will take a lot of time to retransmit, and if the amount of data transferred at one time is small, the response of the transfer result will be relatively large. I ended up spending a lot of time. In other words, it has been practically difficult to transfer data efficiently.

Therefore, electronic devices that are prone to noise often employ control devices that transfer data asynchronously and serially. However, with such a control device, it is not only difficult to increase the transfer speed, but also because the transfer speed is inherently slow, there is no time to perform retransmission or other processing when a transfer error occurs. was there.

[Purpose of the invention]

In view of these circumstances, it is an object of the present invention to provide a control device for a copying machine, etc., which performs serial data transfer in an externally synchronized manner and is capable of quickly dealing with errors when they occur.

[Structure of the invention]

In the present invention, in an electronic device such as a copying machine that includes a main data processing section and a secondary data processing section in a control device and transfers data in a distributed processing format, the main data processing section includes:
■The source of the clock that is supplied to each part; ■Clock monitoring means for monitoring the state of the clock that has bypassed other data processing parts; ■Means for detecting errors in the transferred data; and ■This means. means for at least temporarily stopping clock transmission when an error is detected. The secondary data control unit also includes: (1) clock monitoring means for monitoring the status of the clock sent directly from the main data processing unit or via another data processing unit, and (2) detecting errors in the transferred data. and (2) means for at least temporarily stopping clock transmission when an error is detected by the means. Then, on the data sending side, when a clock interruption is detected by the clock monitoring means, the data transfer error can be recognized as being detectable, and necessary measures such as data retransmission can be quickly executed. make it happen.

〔Example〕

The present invention will be described in detail below with reference to Examples.

The drawing shows a part of a control device used in an electronic copying machine. The left half portion surrounded by a broken line in the figure constitutes the main data processing section 11, which is a portion that controls the control of the copying machine. Further, the right half portion similarly surrounded by a broken line constitutes a subordinate data processing section 12 that controls one of the main functional sections such as a document feeding device and a collating device. That is, although not shown in the figure, a plurality of sets of subordinate data processing sections 12 are connected to the main data processing section 11.

The CPU 14 of the main data processing section 11 is connected to a ROM (Read Only Memory) and a RAM (Random Access Memory) (also not shown) through an internal bus (not shown), and operates the copying machine according to a program written in the ROM. It is designed to perform comprehensive control. The subordinate data processing unit 12 also includes a CPU 15,
Similarly, ROM, RAM,
It is connected to various sensors, morphs, electromagnetic clutches, etc., and controls their main functions. Note that the main data processing section not only controls the respective main functional sections, but can also control main functions such as, for example, the control of the copying process.

Now, the main data processing section 11 and the secondary data processing section 1ri
During s t 2, it is necessary to exchange various data in order to ensure proper operation of the copying machine as a whole.

For example, when a print start button (not shown) is pressed, the main data processing section 11 switches to the secondary data processing section 12.
It is necessary to send data instructing the document feeder to feed the document. In addition, on the side of this secondary data processing unit 12, if a paper jam occurs when withdrawing the original, or any other trouble occurs, data notifying this is sent to the main data processing unit 11, and other secondary data It is necessary to make it possible to take countermeasures such as stopping the operation of the T-coupler, which is the processing unit, and displaying trouble status.

In order to enable such data transfer, the main data processing section 11 is provided with a serial interface 16 and a clock generator 17. The serial interface 16 is supplied with a select signal 18 from the CPU 14, and a write/write signal 19 is supplied with a write (wr) signal.
ite), write 8-bit parallel transfer data 21.

This is then converted into serial data, and a start bit, stop bit, and parity bit are added. The transfer data created in this manner is sent out bit by bit to the data line 23 in synchronization with the clock 22 output from the clock generator 17.

By the way, this data processing section 11 is provided with an AND gate 24 that controls the passage of the clock 22, and when the error signal 25 is at the L (low) level (an error detected state), the gate is closed and the clock is turned on. Sending of the clock 22 to the transmission line 26 is prevented. At the stage when sending out serial transfer data is started, the error signal 25 is reset to H (high) level and the clock 22
is ready to be output. At the same time, an enable signal 28 is supplied to the timer 27 in the main data processing section 11, and the timer 27 is set to a state in which it can interrupt the CP 1114.

A serial interface 31 disposed within the secondary data processing unit 12 receives serial transfer data in synchronization with the clock 22, converts it to parallel data, and after performing a parity check, divides the data. Interrupts the CPU 15 by the input signal 32.CPL1
15 receives the transferred data. This secondary data processing unit 12 is also provided with a timer 33, but interrupts caused by this timer 33 are masked when transfer data is received.

Transfer of data from the secondary data processing section 12 to the main data processing section 11 is performed in the same manner as described above. In other words, the serial interface 3 is connected to the select signal 35.
1 is selected and the read/write signal 36 is set to the write state, transfer data is sent to the data line 37. At the start of this serial data transfer, an enable signal 38 is supplied to the timer 33. Also, the error signal 39 is set to H level, the AND gate 41 is opened, and the clock 22 is transmitted to the clock transmission line 42.
It will be sent to

By the way, in the control device of this embodiment, the clock 22 output from the clock generator 17 of the main data processing section 11
is supplied to the timer 33 in the slave data processing section 12 via the AND gate 24 and the clock transmission line 26. The clock 22 supplied to the secondary data processing unit 12 via this clock transmission line 26 is supplied to the timer 27 in the main data processing unit 11 via an AND gate 41 and another tarlock transmission line 42. Timers 27.33 in both data processing units 11.12 measure the time that the manually input signal is held at L level. When this reaches a predetermined time longer than half a cycle of the clock 22, a time-up is performed and an interrupt is issued to the CPU 14 or 15 in its own data processing section.

Now, suppose that an error is detected in the data on the side of the subordinate data processing section 12. In this case, the CPU 15 activates, for example, a one-shot multi-bye break (not shown) to hold the error signal 39 at the H level for a predetermined period of time. This time is longer than half a cycle of the clock 22, and is usually set to two to several clocks.

As a result, the clock transmitted through the clock transmission line 42 is interrupted during that time, and the timer 27 on the main data processing section 11 side is tied up. The resulting interrupt signal 44 causes the CPU i 4 to start interrupt processing, and preparations are made to retransmit the predetermined unit of data transferred immediately before. Retransmission of data occurs after clock transmission line 42 resumes transmitting clock 22 again. When an error is detected in the data on the main data processing section 11 side, the timer 33 on the secondary data processing section 12 side times up and an interrupt signal 4 is detected.
5 causes an interrupt to the CPU 15. In this case, data is retransmitted from the subordinate data processing section 12.

Main data processing section 11 and secondary data processing section 12
each counts the number of data retransmissions, and if the number of retransmissions within a unit of time exceeds a certain number, it is assumed that the data processing unit on the other side has failed, and predetermined processing such as displaying the details of the problem on the display is performed. execution can be started.

〔Effect of the invention〕

According to the present invention, since the same clock is used to transfer data between the data processing units, the data transfer speed can be easily increased by increasing the clock speed. Moreover, if an error occurs in data transfer,
This can be immediately notified to the sending side using the clock transmission line, and reprocessing when an error occurs can be sufficiently speeded up.

[Brief explanation of drawings]

The drawing is a block diagram showing part of a control device in an embodiment of the present invention. 11... Main data processing section, 12...
・Subordinate data processing unit, 14.15...cpu
. 17... Clock generator, " 27.33... Timer, 24.41... AND gate, 26.42...
...Tarotsuk transmission line. −−−−−−−−−'−J

Claims (1)

[Claims] In an electronic device that includes a main data processing unit and one or more secondary data processing units and transfers data between these data processing units in a distributed processing format, there are The main data processing section is provided with a clock monitoring means for monitoring the state of the clock that has bypassed the data processing section, and the secondary data processing section is provided with a clock monitoring means that monitors the state of the clock that has bypassed the main data processing section. A clock monitoring means is provided to monitor the status of the transmitted clock, and each of the main and slave data processing units is further provided with means for detecting an error in the transmitted data, and a means for detecting an error in the transmitted data. and a means for at least temporarily stopping clock transmission at a certain point in time, and when the own clock monitoring means detects an interruption or stop of clock transmission when the own data processing unit sends data, the data A control device for a copying machine, etc., characterized in that it detects an error in the transfer of data.