Chapter 16 Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12XE-Family Reference Manual , Rev. 1.19
632
Freescale Semiconductor
Read: For transmit buffers, anytime when TXEx flag is set (see
Section 16.3.2.7, “MSCAN Transmitter
”) and the corresponding transmit buffer is selected in CANTBSEL (see
Section 16.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)
”). For receive buffers,
only when RXF flag is set (see
Section 16.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)
Write: For transmit buffers, anytime when TXEx flag is set (see
Section 16.3.2.7, “MSCAN Transmitter
”) and the corresponding transmit buffer is selected in CANTBSEL (see
Section 16.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)
”). Unimplemented for
receive buffers.
Reset: Undefined (0x00XX) because of RAM-based implementation
16.3.3.1
Identifier Registers (IDR0–IDR3)
The identifier registers for an extended format identifier consist of a total of 32 bits; ID[28:0], SRR, IDE,
and RTR bits. The identifier registers for a standard format identifier consist of a total of 13 bits; ID[10:0],
RTR, and IDE bits.
= Unused, always read ‘x’
Figure 16-25. Receive/Transmit Message Buffer — Standard Identifier Mapping
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
IDR0
0x00X0
R
ID10
ID9
ID8
ID7
ID6
ID5
ID4
ID3
W
IDR1
0x00X1
R
ID2
ID1
ID0
RTR
IDE (=0)
W
IDR2
0x00X2
R
W
IDR3
0x00X3
R
W
= Unused, always read ‘x’
Figure 16-24. Receive/Transmit Message Buffer — Extended Identifier Mapping (continued)
Register
Name
Bit 7
6
5
4
3
2
1
Bit0
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
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available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages