Infineon Technologies TC1728 User Manual page 1324

(RBUSY = BUSY = 1). This indicates that bit fields PANAR1 and PANAR2 are going to
be updated by the list controller in the following way:
1. The message number of the message object taken from the list of unallocated
elements is written to PANAR1.
2. If ERR (bit 7 of PANAR2) is set to 1, the list of unallocated elements was empty and
the command is aborted. If ERR is 0, the list was not empty and the command will be
performed successfully.
The results of a dynamic allocation command are written before the list controller starts
the actual allocation process. As soon as the results are available, RBUSY becomes
inactive (RBUSY = 0) again, while BUSY still remains active until completion of the
command. This allows the user to set up the new message object while it is still in the
process of list allocation. The access to message objects is not limited during ongoing
list operations. However, any access to a register resource located inside the RAM
delays the ongoing allocation process by one access cycle.
As soon as the command is finished, the BUSY flag becomes inactive (BUSY = 0) and
write accesses to the Panel Control Register are enabled again. Also, the "No Operation"
command code is automatically written to the PANCTR.PANCMD field. A new command
may be started any time when BUSY = 0.
All fields of the Panel Control Register PANCTR except BUSY and RBUSY may be
written by the user. This makes it possible to save and restore the Panel Control Register
if the Command Panel is used within independent (mutually interruptible) interrupt
service routines. If this is the case, any task that uses the Command Panel and that may
interrupt another task that also uses the Command Panel should poll the BUSY flag until
it becomes inactive and save the whole PANCTR register to a memory location before
issuing a command. At the end of the interrupt service routine, the task should restore
PANCTR from the memory location.
Before a message object that is allocated to the list of an active CAN node shall be
moved to another list or to another position within the same list, bit MOCTRn.MSGVAL
("Message Valid") of message object n must be cleared.
User's Manual
MultiCAN, V2.24
Controller Area Network Controller (MultiCAN)
20-31
TC1728
V1.0, 2011-12