pyctools/pyc/protocol.txt

This file contains information on the protocol used by teh IFI Loader.

The protocol is packet based. The PC sends a packet to the controller, and the controller sends its response.

== Packet structure ==
Each packet follows the same format:
 0F 0F <BODY> 04
Where <tt>&lt;BODY&gt;</tt> is the escaped form of the format:
 <CMD> <DATA> <HASH>
; CMD : A single-byte identifier for the command, which is as follows:
:* 00 - INIT
:* 01 - READ
:* 02 - WRITE
:* 08 - RESET
:* 09 - ERASE
; DATA : The arguments to the command. May be 0 bytes.
; HASH : The hash of the rest of the body. Hash is calculated as 2's complement (~sum + 1).

=== Escaping ===
Because of the special meaning of 0F, 04, and 05, whenever these data bytes appear in the body, they are prepended by a 05. That is, if the packet body is:
 09  E0 00 08 00 00  0F
The packet sent is:
 0F 0F  09  E0 00 08 00 00  05 0F  04

== Commands ==
=== INIT ==
; Number : 00
; Request Data : 02
; Response Data : 02 00 01

This packet is used to test if the controller is in program mode, and likely initialize it.

=== READ ===
; Number : 01
; Request Data : <LENGTH> <ADDRESS>
:; LENGTH : The ammount of data to return
:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
; Response Data : <LENGTH> <ADDRESS> <DATA>
:; LENGTH : The ammount of data returned
:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
:; DATA : The data itself, the lowest address transmitted first

This command reads a location in memory. Note that the memoryspace is not the same as program memory or EEPROM. See Microchip documentation.

=== WRITE ===
; Number : 02
; Request Data : <ADDRESS> <DATA>
:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
:; DATA : The data itself, the lowest address transmitted first
; Response Data : (Empty packet)

Write data to memory. The memoryspace is the same as the READ command.

There is a response packet, but its data is empty, ie it consists only of a command and a hash.

=== RESET ===
; Number : 08
; Request Data : 40
; Response Data : (None)

Causes the controller to reset, exiting program mode and executing the program. No response packet is sent.

=== ERASE ===
; Number : 09
; Request Data : <BLOB>
:; BLOB : a 5-byte piece of data
; Response Data : (Empty packet)

Causes memory to be erased. The exact nature of the request data is unknown.

There is a response packet, but its data is empty, ie it consists only of a command and a hash.
1	This file contains information on the protocol used by teh IFI Loader.
2
3	The protocol is packet based. The PC sends a packet to the controller, and the controller sends its response.
4
5	== Packet structure ==
6	Each packet follows the same format:
7	0F 0F <BODY> 04
8	Where <tt><BODY></tt> is the escaped form of the format:
9	<CMD> <DATA> <HASH>
10	; CMD : A single-byte identifier for the command, which is as follows:
11	:* 00 - INIT
12	:* 01 - READ
13	:* 02 - WRITE
14	:* 08 - RESET
15	:* 09 - ERASE
16	; DATA : The arguments to the command. May be 0 bytes.
17	; HASH : The hash of the rest of the body. Hash is calculated as 2's complement (~sum + 1).
18
19	=== Escaping ===
20	Because of the special meaning of 0F, 04, and 05, whenever these data bytes appear in the body, they are prepended by a 05. That is, if the packet body is:
21	09 E0 00 08 00 00 0F
22	The packet sent is:
23	0F 0F 09 E0 00 08 00 00 05 0F 04
24
25	== Commands ==
26	=== INIT ==
27	; Number : 00
28	; Request Data : 02
29	; Response Data : 02 00 01
30
31	This packet is used to test if the controller is in program mode, and likely initialize it.
32
33	=== READ ===
34	; Number : 01
35	; Request Data : <LENGTH> <ADDRESS>
36	:; LENGTH : The ammount of data to return
37	:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
38	; Response Data : <LENGTH> <ADDRESS> <DATA>
39	:; LENGTH : The ammount of data returned
40	:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
41	:; DATA : The data itself, the lowest address transmitted first
42
43	This command reads a location in memory. Note that the memoryspace is not the same as program memory or EEPROM. See Microchip documentation.
44
45	=== WRITE ===
46	; Number : 02
47	; Request Data : <ADDRESS> <DATA>
48	:; ADDRESS : The location of the data (in terms of PIC programmers), in little endian format
49	:; DATA : The data itself, the lowest address transmitted first
50	; Response Data : (Empty packet)
51
52	Write data to memory. The memoryspace is the same as the READ command.
53
54	There is a response packet, but its data is empty, ie it consists only of a command and a hash.
55
56	=== RESET ===
57	; Number : 08
58	; Request Data : 40
59	; Response Data : (None)
60
61	Causes the controller to reset, exiting program mode and executing the program. No response packet is sent.
62
63	=== ERASE ===
64	; Number : 09
65	; Request Data : <BLOB>
66	:; BLOB : a 5-byte piece of data
67	; Response Data : (Empty packet)
68
69	Causes memory to be erased. The exact nature of the request data is unknown.
70
71	There is a response packet, but its data is empty, ie it consists only of a command and a hash.