[Uisp-dev] [RFC] New fuse options

[Theodore A. Roth]

Hi,

To read the fuses, you can currently do this:

  address@hidden src]$ ./uisp -dprog=stk500 -dserial=/dev/stk500 
  -dpart=atmega128 --segment=fuse --download
  Atmel AVR ATmega128 is found.
  Downloading: fuse
  S00700006675736545
  S1080000E11900FFFFFF
  S5030001FB
  S9030000FC

Then, you could modify the srec out and write it back to the device. I
think this is sub-optimal since the user would then have to hand edit the
srec file and calculate the new checksum. Besides, why should you have to
muck with all the fuses and lock bits just to change one byte?

Alternatively, there's the terminal mode I've already demostrated in a 
previous post.

The attached patch shows the new command line options I'm proposing to 
implement. Once implemented, "--rd_fuses" will dump the state of all the 
fuses and lock bits (plus calibration byte if available). From there, 
changing the fuse bits would be done as such (for example, setting fuse 
low to 0xe4):

  $ ./uisp -dprog=stk500 -dserial=/dev/stk500 -dpart=atmega128 --rd_fuses
  <some output yet to be determined>
  $ ./uisp -dprog=stk500 -dserial=/dev/stk500 -dpart=atmega128 --wr_fuse_l=0xe4

How's that sound?

Ted Roth


Index: src/Main.C
===================================================================
RCS file: /cvsroot/uisp/uisp/src/Main.C,v
retrieving revision 1.2
diff -u -r1.2 Main.C
--- src/Main.C  27 May 2002 02:41:01 -0000  1.2
+++ src/Main.C  30 May 2002 20:19:21 -0000
@@ -75,9 +75,11 @@
 "             [-dserial=device] [-dpart=name|no]\n"
 "             [-dspeed=1200|2400|4800|9600|19200|38400|57600|115200]"
 "\n"
-"             [--upload] [--verify] [--erase] [--lock] [if=input_file]\n"
+"             [--upload] [--verify] [--erase] [if=input_file]\n"
 "             [--download] [of=output_file]\n"
-"             [--segment=flash|eeprom|fuse] [--terminal]\n\n"
+"             [--segment=flash|eeprom|fuse] [--terminal]\n"
+"             [--rd_fuses] [--wr_fuse_l=byte] [--wr_fuse_h=byte]\n"
+"             [--wr_fuse_e=byte] [--wr_lock=byte]\n\n"
 "Programming Methods:\n"
 "  -dprog=avr910    Standard Atmel Serial Programmer/Atmel Low Cost 
Programmer\n"
 "         pavr      http://avr.jpk.co.nz/pavr/pavr.html\n";
@@ -125,9 +127,15 @@
 "  --verify     Verify \"input_file\" (processed after the --upload 
opt.)\n"
 "  --download   Download AVR memory to \"output_file\" or stdout.\n"
 "  --erase      Erase device.\n"
-"  --lock       Write lock bits.\n"
 "  --segment    Set active segment (auto-select for AVA Motorola 
output)\n"
 "\n"
+"Fuse/Lock Bit Operations:\n"
+"  --rd_fuses   Read all fuses and print values to stdout\n"
+"  --wr_fuse_l  Write fuse low byte\n"
+"  --wr_fuse_h  Write fuse high byte\n"
+"  --wr_fuse_e  Write fuse extended byte\n"
+"  --wr_lock    Write lock bits\n"
+"\n"
 "Files:\n"
 "  if           Input file for the --upload and --verify functions in\n"
 "               Motorola S-records (S1 or S2) or 16 bit Intel format\n"