View source for Start Development

Sorry, not complete yet, you will find some starting point in the examples delivered with the toolchain...





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=== Todo ===

howto compile examples



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=== Blackfin programming reference ===
: If you are new to blackfin development it may be a good idea to read this document.
: [http://www.analog.com/static/imported-files/processor_manuals/bf533_hwr_Rev3.4.pdf Blackfin Processor Hardware Reference]

=== Pitfalls ===

; Alignment
: Every command must be word aligned. When you access the memory, word accesses must be word aligned, long word accesses must be long word aligned. 
: '''Don't''' use the .align directive . It doesn't works with the toolchain. Use .byte directives to do that.

; Subroutines / Calls
: Every subroutine that calls subroutines must start with LINK and end with UNLINK to save the return address to the stack. The blackfin CPU doesn't do that automaticly.

Example:
<pre>
sub:
  LINK 0x0

  ...
  CALL sub2
  ...

  UNLINK
  RTS
</pre>

; STOP-Mode
: Switch your scope to the STOP-Mode if you don't need capturing during your software is working. Sometimes i got unpredictable crashs when the device was in AUTO-Mode. Hope to find a reason for this thing soon.

=== Unlock the Keyboard ===
: If you need keyboard interaction, first you should unlock the keyboard for user inputs.
: This lines will do the job:
<pre>
  R0=0
  CALL Set_KeyLock
</pre>
: The keyboard is locked, because the serial interface is used to upload and start your software.
: You can see that its locked if the only keycode you get is KC_KEYLOCK (0xc9).