MPC555
/
MPC556
CAN 2.0B CONTROLLER MODULE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
16-32
16.7.10 Receive Buffer 14 Mask Registers
RX14MSKHI —
Receive Buffer 14 Mask Register High
0x30 7094, 0x30 7494
RX14MSKLO —
Receive Buffer 14 Mask Register Low
0x30 7096, 0x30 7496
The receive buffer 14 mask registers have the same structure as the receive global
mask registers and are used to mask buffer 14.
16.7.11 Receive Buffer 15 Mask Registers
RX15MSKHI —
Receive Buffer 15 Mask Register High
0x30 7098, 0x30 7498
RX15MSKLO —
Receive Buffer 15 Mask Register Low
0x30 709A, 0x30 749A
The receive buffer 15 mask registers have the same structure as the receive global
mask registers and are used to mask buffer 15.
16.7.12 Error and Status Register
This register reflects various error conditions, general status, and has the enable bits
for three of the TouCAN interrupt sources. The reported error conditions are those
which have occurred since the last time the register was read. A read clears these bits
to zero.
Table 16-20 RXGMSKHI, RXGMSKLO Bit Descriptions
Bit(s)
Name
Description
0:31
MIDx
The receive global mask registers use four bytes. The mask bits are applied to all receive-
identifiers, excluding receive-buffers 14 and 15, which have their own specific mask regis-
ters.
Base ID mask bits MID[28:18] are used to mask standard or extended format frames. Ex-
tended ID bits MID[17:0] are used to mask only extended format frames.
The RTR/SRR bit of a received frame is never compared to the corresponding bit in the mes-
sage buffer ID field. However, remote request frames (RTR = 1) once received, are never
stored into the message buffers. RTR mask bit locations in the mask registers (bits 20 and
zero) are always zero, regardless of any write to these bits.
The IDE bit of a received frame is always compared to determine if the message contains a
standard or extended identifier. Its location in the mask registers (bit 19) is always one, re-
gardless of any write to this bit.
ESTAT —
Error and Status Register
0x30 70A0
0x30 74A0
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
BITERR
ACK
ERR
CRC
ERR
FORM
ERR
STUFF
ERR
TX
WARN
RX
WARN
IDLE
TX/RX
FCS
0
BOFF
INT
ERR
INT
WAKE
INT
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..