TC1796
Peripheral Units (Vol. 2 of 2)
Controller Area Network (MultiCAN) Controller
User’s Manual
22-108
V2.0, 2007-07
MultiCAN, V2.0
Field
Bits
Type Description
AM
[28:0]
rw
Acceptance Mask for Message Identifier
Bit field AM is the 29-bit mask for filtering incoming
messages with standard identifiers (AM[28:18]) or
extended identifiers (AM[28:0]). For standard
identifiers bits AM[17:0] are “don’t care”.
For TTC based transmit acceptance filtering
(MOARn.PRI = 00
B
) register MOAMRn is used to
specify the transmit column/row in which this
message object may be transmitted in a time-
triggered communication. It is then no longer used as
an identifier mask. This means that all identifier bits
are used for receive acceptance filtering. In this case
AMR contains the following information:
•
MOAMR[5:0] = CYCLE
•
MOAMR[13:8] = MCYCLE
•
MOAMR[21:16] = COLUMN
•
MOAMR[29:24] = MCOLUMN
where CYCLE is the cycle count (transmit row) and
COLUMN is the transmission column of the system
matrix. MCYCLE and MCOLUMN are acceptance
masks for matching CYCLE and COLUMN against
the actual position within the system matrix of the
time-triggered communication network. Message
object n may be transmitted only if CYCLE and
COLUMN match the actual matrix position (given by
CYCTMR.BCC and CYCTMR.CSM). If more than
one object with valid transmit request matches a
given matrix position, the actually transmitted
message object is chosen by list order.
MIDE
29
rw
Acceptance Mask Bit for Message IDE Bit
0
B
Message object n accepts the reception of
both, standard and extended frames.
1
B
Message object n receives frames only with
matching IDE bit.
0
[31:30] rw
Reserved
Read as 0 after reset; value last written is read back.