RE: JTAG debugging at Cornell

Go To Last Post
9 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

hi
i'm using avr butterfly
my question is i'm want to use 16 bit lcd display for to my avr and i want to use JTAG port to connect it and it say that that i must disable that port to connect my lcd on it.
how i want to disable this port(JTAG)?

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Quote:

how i want to disable this port(JTAG)?

What does the datasheet say about JTAGEN fuse? What does the datasheet say about disabling JTAG? (Surely a datasheet search on "jtag" will quickly bring you to the pertinent section.) What is a "16-bit LCD display"? How are you going to free a whole bunch of pins on a nearly "full" design?

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

can u give me the link that show how to disable datasheet.
i'm not using butterfly lcd but i use 16 pin lcd display as my display.
i want to use port D and JTAG port to connect my lcd display
port B is for my LCD

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Go to Atmel's site and download the datasheet for the Mega169. Use Acrobat Reader to search for the strings as suggested.

You are using port D, or port B, or both for your LCD?

When you look at the Butterfly schematics, are all those pins "free" for your use? [I'd think not. Port D goes to LCD segments; port B goes to devices (dataflash; joystick)]

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

im only using port d because on port b i'm using it for my keypad

yeah
you right
not all pin are free to use
that's why i want to use JTAG port

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

amiraliff

I'm going to split your hijack off this thread and call it "Disabling JTAG on Butterfly"

Cliff

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

oh
sorry
my mistake

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The Butterfly, with mostly dedicated pins, seems like the wrong place to start for a keypad+character LCD project as it already has joystick+segment LCD.

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I discuss this in my "Butterfly Alternate Pin Uses" pdf file that you can get from the downloads on my website.

Smiley