Firmware User Manual (AE-step)
21
Revision 1.02
2019-04-24
TLE984x Firmware User Manual
Boot Strap Loader (BSL)
Figure 4-2 Passphrase Content
For LIN communication, the passphrase frames are encapsulated by sync break, sync char, protected ID, NAD
and checksum byte fields. A passphrase frame is rejected in case of incorrect received NAD or checksum bytes.
For FastLIN communication, the frames are extended by the checksum byte. Details about the encapsulation
are given in
.
The BootROM ignores and rejects all received LIN and FastLIN frames if the communication is still locked. This
rejection includes frames with valid NAD and checksum fields. It does not reply to any received passphrase
frames.
The NAC timeout stops when the communication is unlocked after receiving the second valid passphrase
frame. For more details about NAC timout, refer to
4.1.5
BSL Message Parsing & Responses
The BSL protocol provides single message commands and multimessage commands. A message state
machine is implemented, which first collects all command-related messages before executing the command.
It periodically polls the underlying interface protocol layer (e.g. LIN protocol layer) to collect all frames
belonging to a BSL command.
Command Message State Machine
gives an overview of the BSL command message state machine.
BSL20_ PASSPHRASE
.
0
0x46
‚F‘
1
0x4C
‚L‘
2
3
4
5
6
0x49
‚I‘
0x4E
‚N‘
0x50
‚P‘
0x41
‚A‘
0x53
‚S‘
Passphrase Frame #1:
0
0x53
‚S‘
1
0x50
‚P‘
2
3
4
5
6
0x48
‚H‘
0x52
‚R‘
0x41
‚A‘
0x53
‚S‘
0x45
‚E‘
Passphrase Frame #2: