Atmel AVR042 Application Note Download Page 15 | Manualshive

Page: 15 / 17

background image

AVR Hardware Design Considerations [APPLICATION NOTE]

Atmel-2521M-AVR-Hardware-Design-Considerations_ApplicationNote_092014

15

(B)

(C)

«
...
13
14
15
16
17
»

Summary of Contents for AVR042

Page 1: ...on to potential design problems rather than being an exhaustive walk through of how to design applications using the AVR microcontrollers This document is thus a collection of information from existin...

Page 2: ...SPI Programming Interface 6 3 1 1 Shared Use of SPI Programming Lines 7 3 2 JTAG Interface 7 3 2 1 Shared Use of JTAG Lines 8 3 3 PDI Interface 9 3 3 1 External Reset Circuitry 9 3 4 TPI Interface 10...

Page 3: ...tor Figure 1 1 Incorrect Decoupling Figure 1 1 shows an example of insufficient decoupling The capacitor is placed too far away from the microcontroller creating a large high current loop The power an...

Page 4: ...n the same manner as the digital supply voltage AREF must also be decoupled a typical value for the capacitor is 100nF If a separate analog ground AGND is present the analog ground should be separated...

Page 5: ...since this is not internally provided due to High Voltage Programming Alternatively or in addition a Zener diode can be used to limit the RESET voltage relative to GND The Zener diode is highly recomm...

Page 6: ...Tools help for further information on which interfaces are supported by the device and how to connect the programming tool 3 1 SPI Programming Interface On devices that use a Serial Peripheral Interfa...

Page 7: ...d to have only one ISP interface on the target board the ISP programming can be designed so that only one of the AVR devices is provided with a SPI clock at a time All other SPI lines can then be shar...

Page 8: ...inciple is shown in Figure 3 4 and is explained in further detail in the AVR Tools help file Figure 3 4 JTAG Daisy Chain Protection resistors as shown in Figure 3 2 are necessary if the JTAG lines are...

Page 9: ...h Atmel programmers Only two pins on the device are needed for use of this interface RESET also called PDI_CLK and the dedicated PDI_DATA pin The target s voltage supply is made available to allow for...

Page 10: ...e to the fact that the use of these clock sources is not well understood This section therefore treats the topic of using crystals and ceramic resonators in relation to Atmel AVR MCUs The description...

Page 11: ...s refer to both devices Table 4 1 Style tt table title Ceramic Resonator Quartz Crystal Aging 3000ppm 10ppm Frequency tolerance 2000 5000ppm 20ppm Frequency temperature characteristics 20 50ppm C 0 5p...

Page 12: ...symmetric layout so that CL1 CL2 C and CL1S CL2S CS then the external capacitors can be determined by Equation 4 2 CS can be estimated to be 5pF 10pF Equation 4 2 S L C C C 2 4 3 Recommended Capacito...

Page 13: ...counter can through this feature be used for real time functions A 32 768kHz crystal should then be connected to the TOSCx pins of the AVR In some AVRs the internal oscillator circuit used with the re...

Page 14: ...derations APPLICATION NOTE Atmel 2521M AVR Hardware Design Considerations_ApplicationNote_092014 14 Figure 5 1 A Basic Schematic of Required Recommended Connections for ATxmega32A4 B Copper PCB Layout...

Page 15: ...AVR Hardware Design Considerations APPLICATION NOTE Atmel 2521M AVR Hardware Design Considerations_ApplicationNote_092014 15 B C...

Page 16: ...AVR Hardware Design Considerations_ApplicationNote_092014 16 6 Revision History Doc Rev Date Comments 2521M 09 2014 Fixed some typos in Section 2 1 2521L 07 2013 Updated the diagram of Filters on JTA...

Page 17: ...NESS INTERRUPTION OR LOSS OF INFORMATION ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES Atmel makes no representations or wa...

Reviews:

No comments

Related manuals for AVR042

Brand: ABATEC Pages: 8

VLT AQUA Drive FC 202

Brand: Danfoss Pages: 124

Brand: Danfoss Pages: 2

Brand: Danfoss Pages: 8

Brand: Danfoss Pages: 114

Brand: Danfoss Pages: 24

ECL Comfort 296

Brand: Danfoss Pages: 159

VLT AutomationDrive FC 301

Brand: Danfoss Pages: 78

Brand: Danfoss Pages: 20

Brand: Danfoss Pages: 64

Brand: Harman Kardon Pages: 25

Brand: Uniss Pages: 21

GRAVIMETRIC AUGER FEEDER MGF-ST

Brand: Maguire Products Pages: 47

Brand: Magtrol Pages: 160

Brand: Apricus Pages: 32

Linear Technology ADI Power DC3017A

Brand: Analog Devices Pages: 12

Brand: Greenheck Pages: 4

Brand: zeeltronic Pages: 15

Brands by name

0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Popular brands

Load more brands