diff options
Diffstat (limited to 'downloader/proto.txt')
| -rw-r--r-- | downloader/proto.txt | 52 |
1 files changed, 27 insertions, 25 deletions
diff --git a/downloader/proto.txt b/downloader/proto.txt index e85368e..17dec93 100644 --- a/downloader/proto.txt +++ b/downloader/proto.txt @@ -17,11 +17,13 @@ Command List: Description: ------------ -Every command consits of one byte command code, a fixed number of bytes as -arguments and ends with a XOR checksum over all bytes sent. All data is +Every command consits of one byte command code, one byte length which counts all +bytes of the command including the command code and checksum. The length is followed +by zero or more data and a XOR checksum over all bytes sent. All data is transferred LSB first (aka little endian). All addresses and words are 2bytes long. -Every answer to a command starts with the command code. One byte return value, -optionally some data and a checksum (XOR over all bytes received) +Every answer to a command starts with the command code a length field which counts all +bytes of the answer, one byte return value optionally some data and a checksum +(XOR over all bytes received). The return codes have the following meaning: code | Error @@ -38,10 +40,10 @@ The return codes have the following meaning: identify: ~~~~~~~~~ command: - 1 | <csum> (in this case <csum> will always be 1) + 1 | len=3 | <csum> answer: - 1 | <ret> | version | name | devid | fss | mess | supported | <csum> + 1 | len=22 | <ret> | version | name | devid | fss | mess | supported | <csum> version: 2bytes, protocol version @@ -64,7 +66,7 @@ identify: operation first. mess: - 2bytes, maximum eeprom segment size + 1byte, maximum eeprom segment size This represents the maximum number of eeprom bytes which may be written or read at once. Unlike <fss> value it is ok to write or read less than <mess> bytes. @@ -89,10 +91,10 @@ boot: ~~~~~ command: - 2 | <csum> (in this case <csum> will always be 2) + 2 | len=3 | <csum> answer: - 2 | <ret> | <csum> + 2 | len=4 | <ret> | <csum> This instucts the bootloader to boot to the user application directly (no reset) @@ -101,10 +103,10 @@ reset: ~~~~~~ command: - 3 | <csum> (in this case <csum> will always be 3) + 3 | len=3 | <csum> answer: - 3 | <ret> | <csum> + 3 | len=4 | <ret> | <csum> The device performs a reboot. If the boot condition (i.e.: port pin) is not met this instructs the device to boot to the user application. @@ -114,10 +116,10 @@ read flash: ~~~~~~~~~~~ command: - 4 | addr | <csum> + 4 | len=5 | addr | <csum> answer: - 4 | <ret> | data | <csum> + 4 | len=4+2*<fss> | <ret> | data | <csum> The bootloader reads <fss> words from flash address <addr> and returns it as <data>. @@ -127,10 +129,10 @@ write flash: ~~~~~~~~~~~~ command: - 5 | addr | data | <csum> + 5 | len=5+2*<fss> | addr | data | <csum> answer: - 5 | <ret> | <csum> + 5 | len=4 | <ret> | <csum> The bootloader writes <data> (which has to contain exactly <fss> words) to address <addr> inside the flash. The start address has to be aligned to <fss> boundaries. @@ -142,36 +144,36 @@ read eeprom: ~~~~~~~~~~~~ command: - 6 | addr | len | <csum> + 6 | len=5 | addr | len | <csum> answer: - 6 | <ret> | data | <csum> + 6 | len=4+<len> | <ret> | data | <csum> The bootloader reads <len> bytes from eeprom at address <addr> and returns it as - <data>. len is 2bytes long. + <data>. len is 1byte long. write eeprom: ~~~~~~~~~~~~~ command: - 7 | addr | len | data | <csum> + 7 | len=4+2<len(data) | addr | data | <csum> answer: - 7 | <ret> | <csum> + 7 | len=4 | <ret> | <csum> The bootloader writes <data> (which has to contain exactly <len> bytes) to address - <addr> inside the eeprom. len is 2bytes long and the value must not exceed <mess> bytes. + <addr> inside the eeprom. len is 1byte long and the value must not exceed <mess> bytes. read config: ~~~~~~~~~~~~ command: - 8 | nr | <csum> + 8 | len=3 | nr | <csum> answer: - 8 | <ret> | word | <csum> + 8 | len=6 | <ret> | word | <csum> The bootloader reads and returns the configuration word number <nr>. <nr> is one byte long. @@ -181,10 +183,10 @@ write config: ~~~~~~~~~~~~~ command: - 9 | nr | word | <csum> + 9 | len=5 | nr | word | <csum> answer: - 9 | <ret> | <csum> + 9 | len=4 | <ret> | <csum> The bootloader writes <word> onto configuration word number <nr>. <nr> is one byte long. |