barcode reader application in asp.net RESET in Software

Creator Denso QR Bar Code in Software RESET

RESET
QR Code JIS X 0510 Reader In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Encoding QR In None
Using Barcode creation for Software Control to generate, create QR Code image in Software applications.
Optional Reset Pull Down Switch
Decode QR Code JIS X 0510 In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Encoding QR Code In C#
Using Barcode printer for .NET framework Control to generate, create QR Code image in .NET framework applications.
To PIC Micro _MCLR
QR Code ISO/IEC18004 Drawer In .NET
Using Barcode generation for ASP.NET Control to generate, create QR Code JIS X 0510 image in ASP.NET applications.
QR-Code Generator In Visual Studio .NET
Using Barcode creator for .NET Control to generate, create QR Code JIS X 0510 image in Visual Studio .NET applications.
Figure 15.4 A simple pull-up is usually all that is required to hold the _MCLR or reset line high, allowing the PIC microcontroller to execute.
QR Printer In Visual Basic .NET
Using Barcode encoder for VS .NET Control to generate, create QR-Code image in VS .NET applications.
Creating Code 3 Of 9 In None
Using Barcode generator for Software Control to generate, create Code 39 Extended image in Software applications.
In the con guration registers of mid-range parts, there is a bit known as PWRTE. This bit will insert a 72-ms delay during PIC microcontroller power-up before the rst instruction is fetched and executed. The purpose of this function is to allow the PIC microcontroller s clock to stabilize before the application starts. In low- and high-end PIC microcontrollers, this function is not always available. When the _MCLR pin is made active (pulled low), the oscillator stops until the pin is brought back high. In addition, the oscillator is also stopped during sleep to minimize power consumption. The PWRTE 72 ms is required in these cases as well to ensure that the clock is stable before the application s code starts executing. PWRTE does not have to be enabled if a stable clock is being input to the PIC microcontroller such as in the case where a canned oscillator is used as the PIC microcontroller s clock source instead of a crystal, ceramic resonator, or RC network. Personally, I always use the PWRTE function; the 72 ms really isn t detectable by a user, and it ensures that there always will be a clean power-up. Some PIC microcontrollers that are run at low voltage or using alkaline batteries can be reset by the brown-out reset (BOR) circuitry; in some chips, the brown-out voltage is when Vdd is less than 4.0 V, and in others, this voltage is programmable. The programmable BOR voltage tends to be available in newer PIC microcontroller part numbers, which are able to run on from 2.0 up to 6.0 V. I rarely use the 4.0-V BOR parts and instead opt for the ones with a programmable voltage range. Once power drops below the BOR voltage, the circuit will become active and will hold the PIC microcontroller reset, even though it is receiving a valid voltage for the application.
Drawing Barcode In None
Using Barcode encoder for Software Control to generate, create bar code image in Software applications.
Encoding UPC-A Supplement 2 In None
Using Barcode printer for Software Control to generate, create UPC Code image in Software applications.
INTERNAL RESET CAPABILITIES
Draw EAN-13 In None
Using Barcode generation for Software Control to generate, create EAN 13 image in Software applications.
Generate Barcode In None
Using Barcode creator for Software Control to generate, create barcode image in Software applications.
If the PIC microcontroller you want to use does not have a built-in BOR function and you require it for your application, you can create one using a zener diode and a comparator, as shown in Fig. 15.5. In this circuit, voltage is reduced by a voltage divider to one-third its input. The 1-V source will be compared with the one-third Vcc input. If Vcc goes below 3 V, this circuit will put the PIC microcontroller into reset. The voltage
Leitcode Generator In None
Using Barcode generator for Software Control to generate, create Leitcode image in Software applications.
GS1 DataBar Encoder In Java
Using Barcode generator for Java Control to generate, create GS1 DataBar image in Java applications.
PIC MICROCONTROLLER APPLICATION DESIGN AND HARDWARE INTERFACING
Decoding Code-39 In C#
Using Barcode decoder for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Bar Code Drawer In Java
Using Barcode encoder for Android Control to generate, create barcode image in Android applications.
PIC Micro Vcc
Barcode Creator In Visual Studio .NET
Using Barcode encoder for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Bar Code Scanner In VB.NET
Using Barcode Control SDK for VS .NET Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
Inpdendent Voltage
1D Generator In VS .NET
Using Barcode encoder for .NET Control to generate, create 1D Barcode image in .NET framework applications.
Encoding Data Matrix ECC200 In None
Using Barcode generator for Online Control to generate, create ECC200 image in Online applications.
Vdd + Comparator
_MCLR
Zener Diode
Figure 15.5 A rudimentary brown-out reset (BOR) circuit can be implemented with a zener diode and a comparator.
divider values can be changed for different ratios, and R can be quite high (100 k ) to minimize current drain in a battery-driven application. Many of the more modern PIC microcontroller part numbers have internal power-up reset circuitry, which frees up the _MCLR pin for use as an input. A common use for this pin is RS-232 input using a resistor as a current limiter and providing bit banging software to read the incoming values. If you use the _MCLR/I/O pin in this fashion, make sure that you clamp the pin to ground, as shown in Fig. 15.6. If the incoming negative voltage is not clamped within the PIC microcontroller, the negative voltage could cause the PIC microcontroller to be forced into reset mode. The general-purpose pins are designed with clamping diodes built in and will not allow inputs to be driven outside Vdd or ground. Not clamping the input pins can cause some confusing problems when you rst work with the PIC microcontroller in this type of application.
Copyright © OnBarcode.com . All rights reserved.