cf0d93b179
Nothing is implemented yet, but this should help with the implementation when I finally get the chips from China.
25 lines
877 B
Plaintext
25 lines
877 B
Plaintext
STC12A
|
|
|
|
This is an early STC12 protocol variant; It seems to be used on STC12Cx052 and
|
|
possibly other models. It is a mix of STC89 and STC12 protocol versions.
|
|
|
|
Differences to STC12:
|
|
|
|
* Uses NONE parity instead of EVEN parity.
|
|
|
|
* Checksum calculations are different: only a single-byte modular sum is used.
|
|
|
|
* Baudrate handshake isn't initiated with a type 0x50 packet; this is simply
|
|
skipped.
|
|
|
|
* After the handshake a special ping-pong sequence of 0x80 type packets needs
|
|
to be sent.
|
|
This doesn't appear to serve any purpose - possibly this is just done to
|
|
verify that the connection works reliably. STC12 doesn't require it anymore
|
|
because parity and the improved checksum ensure correct operation.
|
|
|
|
* Erase is acknowledged with type 0x80 packet instead of type 0x00
|
|
|
|
* After flash programming, there is no finish packet, type 0x69, sent; this
|
|
is simply skipped.
|