CN102567693A

CN102567693A - Method for processing abnormal command by ultrahigh-frequency tag

Info

Publication number: CN102567693A
Application number: CN2010106223024A
Authority: CN
Inventors: 沈红伟; 张建平; 苏伟
Original assignee: Beijing CEC Huada Electronic Design Co Ltd
Current assignee: Beijing CEC Huada Electronic Design Co Ltd
Priority date: 2010-12-27
Filing date: 2010-12-27
Publication date: 2012-07-11
Anticipated expiration: 2030-12-27
Also published as: CN102567693B

Abstract

The invention discloses a method for processing an abnormal command by an ultrahigh-frequency tag. In the method, the tag judges the correctness of the received command, if the length of one or more bits of the command is abnormal, the tag ignores the command, and a state machine keeps the current state and waits for a reader to send the next command. The method can realize the following aims of: ensuring that the state machine of the tag cannot be halted even if the tag receives the abnormal command; 2, ensuring that the tag only ignores the current error command and still can correctly process the subsequent commands; and 3, ensuring that the tag can judge whether the command is abnormal at any time and immediately recover the decoding state to the initial state.

Description

A kind of ultrahigh frequency label is to unusual process of commands method

Technical field

The present invention be a kind of ultrahigh frequency electronic tag to unusual process of commands method, this invention is applicable to ultrahigh frequency electronic tag logical design field.

Background technology

When reader and label communication, because carrier wave is interfered, the correct order that reader sends possibly become unusual.When label received the unusual order of being disturbed, must judge this order exactly was not correct order, thereby ignores this order.Simultaneously, the state machine of label should jump to a state correctly, waits for that reader sends next command.

Summary of the invention

The objective of the invention is to develop and a kind ofly can accurately judge current unusual order, method that again can the follow-up correct order of correct handling.Its implementation is following:

1, to each data, quantizes with system clock.

2, label detects that first low level is as delimiter on the data line, and quantized value is deli_cnt.

3, second order digit is according to being tari, and quantized value is tari_cnt, if tari_cnt exceeds the relativeness scope with deli_cnt, can think that this bit data is unusual, and decoded state just resets, and the low level that receives so again is exactly delimiter.

4, the 3rd bit data is RTcal, and quantized value is rtcal_cnt, if rtcal_cnt exceeds the relativeness scope with tari_cnt, can think that this bit data is unusual, and decoded state just resets, and the low level that receives so again is exactly delimiter.

5, four figures is according to being TRcal, and quantized value is trcal_cnt, if trcal_cnt exceeds and rtcal_cnt; Relativeness scope with tari_cnt; Can think that this bit data is unusual, decoded state just resets, and the low level that receives so again is exactly delimiter.

If 6 preceding four figures are according to all correct, what receive afterwards all is data, and quantized value is data_cnt; If data_cnt exceeds the relativeness scope with tari_cnt; Can think that this bit data is unusual, decoded state resets immediately, and the low level that receives so again is exactly delimiter.

7, when receiving arbitrary, make mistakes, state machine does not change current state, waits the reception next command, is still unusual order if detect next time, continues to wait for, and is entirely true up to order.

If carrier wave is interfered, demodulator circuit might receive wrong order at any time, and the order of this mistake possibly influence the reception of next command, and unusual command handling method guarantees that next command again can correctly receive.

Since the order of a correct sign indicating number shape end up next command waveform such as accompanying drawing two.

(1) 1,2,3 positions can only be data-0 or data-1.

(2), then correctly receive if the delimiter command determination is 4 positions

(3) if the delimiter command determination is 3 positions; Then the length of a should be tari; Wherein the length of high level is T1 (two order at interval), can judge that by implementation method 3 tari_cnt exceeds the relativeness scope with deli_cnt, can jump to 4 positions automatically as delimiter

(4) if the delimiter command determination is 2 positions, then the length of b should be tari,

(5) if b is actual data-1, then satisfy implementation method 3, can jump to 3 positions automatically, revert to (1) as delimiter;

If b is actual data-0, can not judge then that (6) a position is RTcal.Can judge that by implementation method 4 rtcal_cnt exceeds the relativeness scope with tari_cnt, delimiter jumps to 4.

(7) if the delimiter command determination is 1 position, the length of c should be tari,

(8) if c is actual data-1, can judge that by implementation method 3 tari_cnt exceeds the relativeness scope with deli_cnt, can jump to 2 positions automatically as delimiter, revert to (4);

(9) if c is actual data-0, the b position is RTcal.Can judge that by implementation method 4 rtcal_cnt exceeds the relativeness scope with tari_cnt, delimier jumps to 4.

Description of drawings

Fig. 1, command format, wherein:

1, first low level is delimiter,

2, bits per inch rising edge end according to this,

3, clk is a system clock, quantizes each data with it.

Fig. 2, completeness explanation

Embodiment

Shown in figure one; With clk each data is counted; And under each rising edge latchs the value of counting, if this count value in the scope of its permission, explains that this bit data is correct; If count value is less than its allowed band or also do not arrive the rising edge count value greater than its allowed band when arriving to rising edge, explain that then this bit data is unusual.

After taking place unusually, counter is zero clearing immediately, after next rising edge arrives, restarts counting again.

Claims

1. a ultrahigh frequency electronic tag is to unusual process of commands method; It is characterized in that the length relative fixed of the several leading bit data of every frame data that reader sends is counted each data with system clock; And the value of counting is latched at each rising edge; Judge according to the relativeness of the length of several bit data of every frame head whether receive data unusual,, explain that this bit data is correct if this count value in allowed limits; If count value was less than allowed band or also do not arrive the rising edge count value greater than allowed band when rising edge arrived; Explain that then this bit data is unusual, counter is zero clearing immediately, after next rising edge arrives, restarts counting again.

Like claim 1 and 2 described ultrahigh frequency electronic tags to unusual process of commands method, it is characterized in that, second reception be tari, tari and delimiter have certain multiple to concern, think that this bit data is unusual if exceed this relation;