Electronic locks for EDA design and implementation (1)

0 introduction

As society's growing material wealth, security, security has become a social concern.

Based on EDA design of electronic locks, with its cheap, safe and reliable, easy to use, was widespread concern. A field programmable logic devices (FPGA) is a design vector to hardware description languages (VHDE) as the main way to Q u a r t u s Ⅱ development software and development system for GW48EDA design tools, design of electronic locks, because of its ability to achieve digital input, digital clear, password, unlock, password change, password, password lock and unlock functions, therefore, able to meet the requirements of the security guard.

1 electronic locks of basic functions

Electronic locks the main functions include:

(1) digital input: press a number key, the corresponding figure is displayed in the rightmost digital tube, while the previously entered all numbers to the left a bit.

Design password is 4 bits, the system can only display the first 4 bits of digital delivery.

(2) digital clear: when you press the clear key to clear all previously entered values, and can be displayed as "--".

(3) password unlock: press 55 # key, you can email the old password password lock.

(4) password changes: after you release the old password, you can make the password change.

Enter any four-digit password number, and press # to enter the digital as the new password.

(5) password locked: enter the new password, press the # key 11, you can make the password lock operation.

(6) password unlock: press the # key 99, and then enter the digital; if the input is consistent with the system store password, password lock can be opened; otherwise you cannot unlock it.

2 electronic structure of the code lock

2.1 electronic locks of the overall structure of the

Electronic locks of the overall structure as shown in Figure 1, which includes password lock input modules, control modules and display modules, etc.

2.2 password lock input module

Password lock input module circuit diagram as shown in Figure 2, it produces by sequential circuits, keyboard scan circuitry, bouncing elimination circuit, keyboard key decoding circuit and storage circuit.

Timing generator used to generate circuit in three different frequency pulse waveform of the work, including the system clock signal, bouncing signals and the Elimination of sampling keyboard scan signals.

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