Datasheet

MSCAN
Register Descriptions
MC9S12DP256 — Revision 1.1
MSCAN
LOOPB — Loop Back Self Test Mode
When this bit is set, the MSCAN performs an internal loop back which
can be used for self test operation. The bit stream output of the
transmitter is fed back to the receiver internally. The RxCAN input pin
is ignored and the TxCAN output goes to the recessive state (logic
‘1’). The MSCAN behaves as it does normally when transmitting and
treats its own transmitted message as a message received from a
remote node. In this state, the MSCAN ignores the bit sent during the
ACK slot in the CAN frame Acknowledge field to ensure proper
reception of its own message. Both transmit and receive interrupts
are generated.
LISTEN — Listen Only Mode
This bit configures the MSCAN as a bus monitor. When the bit is set,
all valid CAN messages with matching ID are received, but no
acknowledgement or error frames are sent out (see Listen-Only
Mode). In addition the error counters are frozen. Listen Only Mode
supports applications which require ‘hot plugging’ or throughput
analysis. The MSCAN is unable to transmit any messages, when
Listen Only Mode is active.
1 = Listen Only Mode activated
0 = normal operation
WUPM — Wake-Up Mode
This bit defines whether the integrated low-pass filter is applied to
protect the MSCAN from spurious wake-up (see MSCAN Sleep
Mode).
1 = MSCAN wakes-up the CPU only in case of a dominant pulse
on the bus which has a length of T
wup
and WUPE=1 in
CANCTL0 (see MSCAN Control 0 Register (CANCTL0)).
0 = MSCAN wakes-up the CPU after any recessive to dominant
edge on the CAN bus and WUPE=1 in CANCTL0.
SLPAK — Sleep Mode Acknowledge
This flag indicates whether the MSCAN module has entered Sleep
Mode (see MSCAN Sleep Mode). It is used as a handshake flag for
the SLPRQ Sleep Mode request. Sleep Mode is active when
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