General Protocol
----------------

- Line based
- LF at end of line, CR is ignored
- Host sends two letter commands optionally followed by paramters on one line
- Target replies with 'OK' or 'ER' optionally followed by information
- Target replies with 'CO' for commands which expect more data from the host.
- After sending a command the host must wait for 'OK' 'ER' or 'CO'.


Commands
--------


Communication test:

>HI
<OK 0.1


Read IDCODE:

>ID
<OK x1C22093


Program:

>PG<IDCODE>
<CO
>binarydata...
<OK

Type      IDCODE
XC3S500E  1C22093



Set Baud Rate:

Baudrate is set in two steps: First the new baud rate is requested by the
host. If the target replies with 'CO' the host must wait one second and
then send the test pattern 'brUUUABC' with the new baud rate. If the target
received the test pattern it replies with 'OK' and keeps the new baud rate,
else it switches back to the previous one.

>BR<X>
<CO
>brUUUABC
<OK

Baud-Rate   X
9600        0
19200       1
38400       2
57600       3
115200      4
230400      5
460800      6
921600      7



Binary Data
-----------

Encoded as printable characters, 6bit per character, charset:
  A-Z, a-z, 0-9, '_', '@'
(A=0, B=1, ..., _=62, @=63)

The data is transferred as lines starting with '~' or '!' followed by
up to 74 encoded data bytes. The last line starts with '!', all others
with '~'.

All '~' lines must contain 72 encoded data bytes which is 54 raw data
bytes.

The first byte of a '!' line must contain the number of raw data bytes
following. This number must be between 1 and 54 including.

Example:

55 0xFF bytes:
~@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
!Aev



See Also
--------

ug332  configuration user guide
  IDCODE page 236