TC1796
System Units (Vol. 1 of 2)
Reset and Boot Operation
User’s Manual
4-26
V2.0, 2007-07
Reset, V2.0
data frames. The acknowledge frame uses the message identifier ACKID that has been
received with the initialization frame. The eight data bytes of the acknowledge frame are
a copy of the data bytes of the recognized initialization frame.
Data Transmission Phase
In the data transmission phase, data frames are sent by the external host and received
by the TC1796. The data frame uses the 11-bit (2-byte) data message identifier DMSGID
that has been sent with the initialization frame. Eight data bytes are transmitted with each
data frame. The first data byte is stored in SPRAM at D400 0000
H
. Consecutive data
bytes are stored at incrementing addresses.
Both communication partners evaluate the data message count DMSGC until the
requested number of CAN data frames has been transmitted. After the reception of the
last CAN data frame, the bootstrap loader software is finished and executes a jump to
address D400 0000
H
. This address is the first 32-bit word location in the SPRAM.
Timing Parameters
There are no general restrictions for CAN timings of the external host. After a reset of
external host and TC1796, the external host can start transmitting initialization frames.
If no acknowledge frame is sent back within a certain time as defined in the external host
(e.g. after a dedicated number of initialization frame transmissions), the external host
can decide that the TC1796 is not able to establish the CAN boot communication link.