JPH0354988A - Data receiver - Google Patents

Abstract

PURPOSE:To allow a period generated for monitoring in the data receiver to coincide with a data arrival period by providing the data receiver with an arithmetic unit for computing the arrival expecting period of receiving data and a timer generating a period for periodically monitoring the arrival of the receiving date in accordance with the computed result. CONSTITUTION:The number of received data is stored in a received data number counter 4 and a data arrival period is stored in a measuring value counter 3 in each data receiving period. When the stored values are proper, a data arrival average period for forecasting the arrival of receiving data is found out by a data reception circuit 1. An interval timer 2 interrupts a data receiving circuit 1 by the interval. Basically, a receiving data monitoring system is adopped to start data receiving process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data receiving device that receives data coming from outside the device via an interface.

[Prior Art] Conventionally, when receiving data from a host via an interface, there are two methods for the data receiving side to start data reception processing: an interrupt method and a received data monitoring method.
Two methods are commonly adopted.

The interrupt method uses special hardware for generating an interrupt, and when reception data is received, an interrupt is generated to start data reception processing.

On the other hand, the received data monitoring method is a method in which the data reception processing device itself periodically monitors the presence or absence of received data at a certain period, and starts data reception processing if the received data is received.

[Problems to be Solved by the Invention] When using the interrupt method, the reception controller as an interface can start data reception processing by a hardware interrupt without being aware of the arrival of reception data. Therefore, wasted processing time of the reception controller is minimized and processing efficiency is increased. However, it requires special hardware to generate interrupts, so
Because the circuit configuration was complicated and the cost increased, it was installed in relatively expensive equipment.

On the other hand, relatively low-cost devices employ the above-mentioned received data monitoring method of monitoring the arrival of received data at certain intervals. However, there is no problem if the cycle monitored by internal processing and the transmission cycle of data arriving from the host match, but if these cycles differ, the processing efficiency of the reception controller deteriorates and the reception throughput decreases. There was a drawback to that.

The purpose of the present invention is to basically start data reception processing using a reception data monitoring method, and to probabilistically predict the reception cycle of data coming from outside the device within the reception device, thereby preventing the above-mentioned The disadvantages of this method and
Simultaneously eliminates the drawbacks that occur with the received data monitoring method,
An object of the present invention is to provide a data receiving device that can improve the efficiency of reception processing.

[Means for Solving the Problems] The data receiving device of the present invention periodically monitors the arrival of received data from outside the device at a certain period, and starts data reception processing when the received data has arrived. It is structured as follows.

Such a structure includes a received data number counter that counts the number of received data that arrives, and a measurement value counter that counts the arrival time of the received data.

Further, a calculation device for calculating the expected arrival cycle of the received data from the received data count counted by the received data number counter and the arrival time counted by the measured value counter, and a device for periodically monitoring the arrival of the received data. and a timer that generates the period according to the calculation result.

[Operation] When received data arrives at this data receiving device from outside the device, the number of received data is measured by a received data number counter, and the arrival time of the received data is measured by a measurement value counter.

When the count value reaches an appropriate value, the expected arrival period of the received data is calculated by the calculation device based on the count value of the received data number counter and the count value of the measured value counter. This expected arrival cycle is the basis for probabilistically predicting the arrival of received data. Depending on the calculation result, an interval for probabilistically predicting the arrival of received data is set in the timer.

Then, each time the interval time elapses, the timer issues an interrupt to the data receiving apparatus for regularly monitoring the arrival of received data.

In this way, the cycle that occurs for monitoring inside the device matches the arrival cycle of data arriving from outside the device, so waste in reception processing can be kept to a minimum.

[Example] Hereinafter, an example of the present invention will be described using FIGS. 1 to 3.

FIG. 1 is a block diagram showing an example of a data receiving apparatus according to the present invention.

Reference numeral 1 denotes a data receiving circuit (receiving controller) as an interface, which incorporates the arithmetic device of the present invention.

The data receiving circuit 1 receives data arriving from a data transmitting device (host) 5 external to the device, temporarily stores it in a buffer, and checks the inside of the bath sofa at the timing cycle output from the interval timer 2 to detect the arrival of received data. Monitor regularly.

If the received data has been received, the data is sent to the data processing device 6 to start data processing.

Furthermore, in order to eliminate the conflict between the monitoring period of the interval timer 2 inside the device and the arrival period outside the device, the average value of the arrival period of received data is calculated by a method that will be described later.

Reference numeral 2 denotes a general-purpose interval timer, which measures the interval between the arrival of received data when the data receiving circuit 1 is measuring the arrival cycle (the interval from steps 201 to 210 in FIG. 2, which will be described later). Create the necessary timing. Furthermore, after measuring the arrival period, the average arrival period of received data is set as the interval time,
Every time this interval time expires, an interrupt is made to the data receiving circuit 1 to monitor the arrival of received data.

Reference numeral 3 denotes a measurement value counter, which is counted up to determine the number of interrupts of the interval timer 2 every time the interval timer 2 interrupts when the data receiving circuit 1 is measuring the arrival cycle. That is, the measurement value counter 3 stores the interval time between the arrival of received data as a count value according to the timing of the interval timer 2. Further, after measuring the arrival period, the average arrival period calculated by the data receiving circuit 1 is stored, and this is set as the interval time of the interval timer 2, thereby making it the reception data monitoring period inside the device.

Reference numeral 4 denotes a received data counter that counts and stores the number of received data arriving from the data transmitter 5.

These interval timer 2, measured value counter 3, and received data number counter 4 are placed under the control of the data receiving circuit 1.

Further, 6 is a device that processes data, such as decoding, in order to obtain necessary information from the data given via the data receiving circuit 1.

The data receiving circuit 1, interval timer 2,
The atII fixed value counter 3, the received data counter 4, and the data processing device 6 constitute the data receiving device of this embodiment.

Next, the operation of the embodiment shown in FIG. 1 will be explained according to the flowcharts shown in FIGS. 2 and 3.

When the data receiving device is powered on, the interval timer 2 is initialized and starts at the initialized timing (interval). At the same time as this start, the data receiving circuit 1 initializes the measured value counter 3 and the received data counter 4 placed under its control (steps 201, 202).

The data receiving circuit 1 repeats data receiving work (work such as sending data to the data processing device 6) in the data receiving process until receiving the first data from the external data receiving device 5, and when the first data is received, the data receiving circuit 1 receives the first data. The received data counter 4 starts counting up at the timing (steps 203, 204, 205).

As mentioned above, the interval timer 2 is a general-purpose timer, and as shown in FIG. 3, it interrupts the data receiving circuit 1 every time the interval time elapses, and the data receiving circuit 1 measures the data arrival cycle. During this period, the measurement value counter 3 is counted up each time an interrupt occurs in order to know the time when data arrives.

In other words, since the interrupt time is known by the initial setting,
The interval time between the arrival of received data can be determined from the number of interruptions stored in the measurement value counter 3 (step 301).
．． 302).

Continuing to step 205, the data receiving circuit l checks the value of the received data number counter 4, determines whether or not it has received a prescribed number of data (for example, several pieces) necessary for calculating the data arrival cycle, and determines whether or not it has received the specified number of data (for example, several pieces). If there is no data, continue receiving data in the reception process until the specified number is reached (step 206).
, 207 and step 205).

When the required number of data is received, at that point the data receiving circuit 1 checks the value of the measured value counter 3 which has been incremented by the interval timer 2 including gtl. If the specified number of data is not received within a certain specified time, that is, within a time that is several times the interval time of interval timer 2, it is determined that this measurement for calculating the data arrival cycle is inappropriate, and counters 3 and 4 are Initialize and redo the measurement (step 208 and steps 202-2)
07)).

If a specified number of data are received within a certain specified time,
The data receiving circuit 1 calculates the average period of data arrival as an expected value as follows.

Data arrival average period = (count value of measurement value counter 3) ÷ (count value of data number counter 4) Then, this calculation result is stored in measurement value counter 3 (step 209
, 210).

Up to this point, the measurement of the data arrival cycle by the data receiving circuit 1 is completed.

Next, the data receiving circuit 1 starts the original receiving process using the average period of data arrival calculated as described above.

The data receiving circuit 1 first confirms the arrival of received data.

If the received data has already arrived, monitoring of the received data using the average period of data arrival cannot be applied to this received data, so the data processing device 6 is made to perform the receiving work by receiving processing for the received data. ,
The process proceeds to the same flow as in the case where the arrival has not arrived (steps 211 and 212), which will be described next.

If it has not arrived, it is assumed that monitoring of the received data based on the data arrival average cycle can be applied, and the interval timer 2 is run at intervals according to the data arrival average cycle stored in the measurement value counter 3 until a timeout occurs. While the interval timer 2 is running toward timeout, it is also possible to have the data processing device 6 perform miscellaneous processing that requires a relatively short processing time to avoid wasting time (steps 213, 214, and 215). ).

When the interval timer 2 times out, the data receiving circuit 1 reconfirms the arrival of the received data, and
If the received data has not arrived contrary to expectations, there is still time until the next arrival, and in the omitted section shown by the dotted line in the figure, processing of the already received data, such as decoding, etc., and a comparatively long processing time are performed. After the data processing device 6 performs a long process, the process returns to the steno knob 211 (step 2
16).

Furthermore, if the received data has arrived as expected, after performing reception processing, the interval timer 2 is started at an interval according to the measurement value counter 3, and the processing is continued in the same manner (steps 212 to 216).

As described above, according to this embodiment, the data transmitting device 5
The reception cycle of data arriving from
Then, the data arrival period is stored in the measured value counter 3, and if the stored value is appropriate, the data reception circuit 1 calculates the data arrival period to predict the arrival period of the received data based on these count values. Find it by ゛And,
The interval timer 2 interrupts the data receiving circuit 1 at intervals according to the determined average cycle of data arrival, and basically uses a received data monitoring method to start data receiving processing. It is.

Therefore, the configuration can be simplified without using special hardware such as an interrupt generation circuit, and the cost of the device can be reduced.

In addition, since the cycle monitored inside the device and the transmission cycle of data arriving from outside the device almost match, the processing time for starting data reception processing in the data reception circuit 1 is shortened to the same level as with the interrupt method, and the data reception Although it is a data monitoring method, processing efficiency can be dramatically increased.

In addition, although the above embodiment describes the case where the arrival period is calculated when the power is turned on, the present invention is not limited to this. It is also possible to provide a timer interrupt cycle.

Further, although the expected arrival period of received data is calculated as an average value, it is not necessarily limited to the average value, and it is also possible to calculate a value closer to the arrival period using other statistical methods.

Furthermore, the calculation result may be used as the interval time of the interval timer as is in the example, but it is possible to shorten or extend it based on the calculation result to make the interval time, thereby making the prediction effect even more effective. It can also be made into something.

[Effects of the Invention] As described above, according to the present invention, when performing data reception processing, the arrival period of received data calculated probabilistically is used as an expected value, so a data reception monitoring method is adopted. However, it is possible to obtain a high throughput rate equivalent to that of interrupt-based reception.

[Brief explanation of drawings]

FIG. I is a block diagram showing an embodiment of a receiving data device for carrying out the data receiving method according to the present invention, FIG.
The same figure is a flowchart illustrating timer interrupt processing. 1, 2, 3, 4.6 are elements constituting the data receiving device, where ■ is a data receiving circuit with a built-in arithmetic unit, 2 is an interval timer, 3 is a measured value counter, 4 is a received data number counter, 6 is a data processing device, and 5 is a data transmitting device that transmits data. Figure 2

Claims (1)

[Claims] In a data receiving device that periodically monitors the arrival of received data from outside the device at a certain cycle and starts data reception processing when the received data has arrived, the number of incoming received data is calculated. A reception data number counter for counting, a measurement value counter for counting the arrival time of the reception data, and arrival of reception data from the reception data count counted by the reception data number counter and the arrival time counted by the measurement value counter. A data receiving device comprising: a calculation device that calculates an expected period; and a timer that generates the period according to the calculation result for periodically monitoring the arrival of received data.