JP2650001B2 - Serial transfer reception completion determination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reception completion judging method in a serial data transmission apparatus, and more particularly to a serial transfer reception completion judging method capable of judging the completion of reception of data other than a fixed format.

In a serial data transmission device for serially transferring data, the format of data to be transmitted is not limited to a fixed format, and the data length may not be constant and the data transmission cycle may not be constant.

[0003] In a serial data transmission apparatus in which data other than the fixed format is sometimes transmitted, the completion of reception of serial data can be determined in a plurality of cases.
It is desired that the reception completion of data other than the standard format can be determined.

[0004]

2. Description of the Related Art FIG. 6 shows a conventional serial transfer reception completion judging method. Serial data receiving device 1
At 0, 11 is an input processing unit, and 12 is an end code (E
TX), an ETX detection unit 13 detects a start code (S
TX), a counter for counting the data length after detection, 14 is a software reception processing unit, and 15 is an input buffer.

[0005] The receiving process in the conventional serial data transmission device shown in FIG. 6 has been performed in the following order. When the input processing unit 11 detects the input of the start code added to the serial data, the writing of data to the input buffer 15 is started. The ETX detection unit 12 checks whether or not an end code is input each time one byte is input. Or counter 13
In, the number of received bytes is counted and compared with the designated length. When the ETX detection unit 12 detects the end code or when the counter 13 counts the reception of the data having the designated data length, the reception completion unit 14 generates a reception completion interrupt to the reception processing unit 14 composed of software.

However, since the data format is not specified, for example, error check data such as BCC is added after the start code, and the data length is not constant and the data transmission cycle is not constant. In some cases, the reception completion determination method of FIG. 6 may not be able to determine the completion of data reception.

Therefore, the software reception processing unit 14
, A timer process is performed, and after a reception process is started, a timer is monitored for a predetermined time, and a process of completing reception is performed when a time-out occurs.

[0008]

In the conventional serial transfer reception completion judging method shown in FIG. 6, in the case of data other than the standard data, a completion interrupt cannot be obtained at the time when the data reception is completed. Therefore, the reception completion must be determined by monitoring the timer. However, there is a problem that the timer value when the reception completion is determined by the timer monitoring must always be set to a value corresponding to the longest data.

Further, since the timer is monitored after the reception process is started in software, the operation time of hardware must be included in the timer value. Further, when the timer value is inappropriate, there is a problem that the reception completion may be determined in the middle of the data.

The present invention has been made to solve the above-mentioned problems of the prior art, and is based on detection of a start code and an end code and their reception timings. , The reception completion timing can be determined for any type of data.
It is an object of the present invention to provide a serial transfer reception completion determination method.

[0011]

According to the serial transfer reception completion judging method of the present invention, when a start code is received in input serial data, an input process is performed, and a first counter 1 for counting the length of received data from detection of the start code. The input processing unit 2 generates an interrupt upon completion of counting of the designated data length, the end code detection unit 3 generates an interrupt when an end code is detected in the input serial data, and the input processing unit 2 and the end code detection unit 3 In the serial data transmission device provided with a reception processing unit 4 for performing a reception completion process by the interruption of, a start code detection unit 6 is provided, and when a start code is detected in input serial data, a timer monitoring interrupt is generated; When the timer monitoring processing unit 7 is provided and the specified time length is counted from the occurrence of the timer monitoring interrupt, An interrupt is generated, a second counter 8 is provided, and the length of the received data is counted from the time of detecting the end code, so that the interrupt is also generated when the second counter 8 counts the designated data length in the end code detection unit 3. Occurs, and the reception processing unit 4
The processing of the reception completion is also performed by the interruption of.

In this case, an interrupt setting section 9 is provided to interrupt from the input processing section 2 based on the count of the designated data length from the start code detection and from the end code detection section 3 based on the detection of the end code. Any one of an interrupt, an interrupt from the end code detection unit 3 based on the count of the designated data length from the end code detection, and an interrupt from the timer monitoring processing unit 7 based on the count of the designated time length from the start code detection. It can be set so as to be selected and input to the reception processing unit 4.

Further, according to the serial transfer reception completion judging method of the present invention, in a serial data transmission apparatus which performs an input process when a start code is received in input serial data, a start of generating an output when a start code is received in the input serial data is provided. A code detector 6, an end code detector 3 that generates an output when an end code is received in the input serial data, and a first counter 1 that generates an output by counting a designated data length after receiving the start code.
And a second counter 8 that generates an output by counting the designated data length from the time when the end code is received, and an interrupt based on the output when the designated data length is counted after the start code is received;
An interrupt based on the end code reception output, an interrupt based on the count of the specified time length after the start code detection output has been generated, and an interrupt based on the output when the specified data length has been counted after the end code has been received are arbitrarily selected to complete the reception. This is to determine.

[0014]

FIG. 1 shows the basic configuration of the present invention. According to the present invention, when the start code is received in the input serial data, the input process is performed, the received data length is counted, an interrupt is generated upon completion of the counting of the designated data length, and the end code is detected in the input serial data. When a serial data transmission device that generates interrupts and performs reception completion processing by these interrupts, a timer monitoring interrupt is generated when a start code is detected in the input serial data, and a timer monitoring interrupt is generated. An interrupt is generated when the specified time length is counted, and an interrupt is also generated when the specified data length is counted by counting the received data length from the end code detection. Can be performed.

In this case, an interrupt based on the count of the designated data length from the start code detection, an interrupt based on the detection of the end code, an interrupt based on the count of the designated data length from the end code detection, and a start code detection It can be set so that the reception completion processing is arbitrarily selected from the interruption based on the counting of the designated time length from the time.

Further, according to the present invention, in a serial data transmission device which performs input processing when a start code is received in input serial data, an output is generated when a start code is received in input serial data, and an end is generated in the input serial data. Generates an output when a code is received, generates an output by counting the specified data length after receiving the start code, and generates an output by counting the specified data length from when the end code is received. An interrupt based on the output during counting,
An interrupt based on the end code reception output, an interrupt based on the count of the specified time length after the start code reception output has been generated, and an interrupt based on the output when the specified data length has been counted after the end code has been received are arbitrarily selected to complete the reception. Can be determined.

[0017]

FIG. 2 shows the configuration of an embodiment of the present invention. The same components as those in FIG. 6 are indicated by the same reference numerals, 16 is an STX detector for detecting a start code, and 17 is an end. A counter that counts the data length after code detection,
Reference numeral 18 denotes a software timer monitoring processing unit that performs timer monitoring after receiving a start code, and 19 denotes an interrupt setting unit that sets interrupt conditions. In the figure, ☆ marks indicate
It shows the interrupt processing.

FIG. 3 is a flowchart showing the process of determining the completion of reception. FIGS. 5 and 6 are flowcharts (1) and (2) showing the data input processing. Hereinafter, the processing of the method of the present invention will be described with reference to the drawings.

When the input processing unit 11 detects the input of the start code added to the serial data, it starts a DMA transfer for writing data to the input buffer 15. Each time one byte is input, the ETX detection unit 12 checks whether or not it is an end code. When the end code is detected, the ETX detection unit 12 interrupts the reception processing unit 14.

When the number of received bytes is counted by the counter 13 and the designated data length is counted, the input processing unit 11 generates an interrupt to the reception processing unit 14. When detecting the input of the start code added to the serial data, the STX detection unit 16
, A timer monitoring interrupt is generated.

The timer monitoring processing unit 18 starts timer monitoring in response to a timer monitoring interrupt from the STX detection unit 16, and when the specified time length has been counted, the reception processing unit 14
Generate an interrupt for When the counter 17 counts the number of bytes received from the end code detection and counts the designated data length, the ETX detection unit 12 generates an interrupt to the reception processing unit 14.

The interrupt setting unit 19 sets an interrupt condition according to an interrupt setting input. The reception processing unit 14 performs reception completion processing based on the interrupt according to the set interrupt condition.

The processing of the completion of reception under each set interrupt condition is performed as follows. It should be noted that the reception completion processing can be performed without setting the interrupt condition.

(1) In the case of a start code detection interrupt, S
In response to an interrupt from the TX detection unit 16, the timer monitoring unit 18 performs timer monitoring. When using other interrupt conditions together, reset the timer when the other conditions are satisfied.

(2) In the case of a specified data length interrupt, the counter 13 is checked every time one byte is input.
The DMA transfer to the input buffer 15 is terminated by raising the interrupt when the specified data length is reached.

(3) In the case of an end code detection interrupt,
When the TX detection unit 12 raises an interrupt to the reception processing unit 14, the DMA transfer to the input buffer 15 ends.

(4) In the case of a designated data length input interrupt after detecting the end code, the counter 17 is checked, and
When the designated data length has been received, an interrupt is issued to the
The MA transfer ends.

[0028]

As described above, according to the present invention, in a serial data transmission device, a serial data transmission device starts with a start code,
In the case of data other than the fixed format data consisting of data of a fixed length ending with the end code, the completion of the reception can be determined. Therefore, even in the case of the opposite device transmitting such data other than the fixed format data,
Serial transfer data can be received.

In particular, according to the present invention, in the case of the reception completion judgment by detecting the end code, the end code is destroyed by specifying other conditions together, and the reception completion cannot be judged. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram showing a configuration of one embodiment of the present invention.

FIG. 3 is a flowchart illustrating a process of determining reception completion.

FIG. 4 is a flowchart (1) showing a data input process.

FIG. 5 is a flowchart (2) showing a data input process.

FIG. 6 is a diagram showing a conventional serial transfer reception completion determination method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First counter 2 Input processing part 3 End code detection part 4 Reception processing part 6 Start code detection part 7 Timer monitoring processing part 8 Second counter 9 Interrupt setting part

Claims (3)

(57) [Claims] An input process is performed when a start code is received in input serial data, and an interrupt is generated by the end of counting of a designated data length of a first counter (1) for counting a received data length from detection of the start code. An input processing unit (2), an end code detection unit (3) that generates an interrupt when an end code is detected in the input serial data, and an interrupt from the input processing unit (2) and the end code detection unit (3). A serial data transmission device comprising: a reception processing unit (4) for performing reception completion processing; a start code detection unit (6) for generating a timer monitoring interrupt when a start code is detected in input serial data; A timer monitoring processor (7) for generating an interrupt when a specified time length is counted from the generation of the monitoring interrupt; And a second counter (8) for counting the length of the received data from the time when the code is detected. When the second counter (8) has counted the specified data length in the end code detection section (3), an interrupt is also generated. A serial transfer reception completion determination method, wherein the reception processing unit (4) is configured to perform reception completion processing in response to an interruption of the timer monitoring processing unit (7). 2. The serial transfer reception completion judging method according to claim 1, wherein the interruption from the input processing unit based on a count of a designated data length from the detection of the start code and the detection of the end code. An interrupt from the end code detecting unit (3) based on a count of a specified data length from the time of detecting the end code, an interrupt from the end code detecting unit (3) based on a count of a specified data length from the time of detecting the end code, and a specified time length from the time of detecting the start code. An interrupt setting unit (9) for arbitrarily selecting an interrupt from the timer monitoring processing unit (7) based on the count and setting it to be input to the reception processing unit (4)
And a serial transfer reception completion determination method. 3. A start code detecting unit for generating an output when a start code is received from input serial data in a serial data transmission device that performs input processing when a start code is received from input serial data.
An end code detector (3) that generates an output when an end code is received in the input serial data, a first counter (1) that generates an output by counting a designated data length after receiving the start code, A second counter (8) for generating an output by counting the designated data length from the time of reception; an interrupt based on an output when the designated data length is counted after the start code is received; and an interrupt based on the occurrence of the end code reception output. Means for arbitrarily selecting an interrupt based on counting of a specified time length after the start code detection output is generated and an interrupt based on an output at the time of counting the specified data length after receiving the end code to determine completion of reception. serial transfers the received completion determining method characterized by comprising.