MPC555
/
MPC556
CAN 2.0B CONTROLLER MODULE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
16-34
16.7.13 Interrupt Mask Register
14
ERRINT
Error Interrupt. The ERRINT bit is used to request an interrupt when the TouCAN detects a
transmit or receive error.
0 = No error interrupt request
1 = If an event which causes one of the error bits in the error and status register to be set
occurs, the error interrupt bit is set. If the ERRMSK bit in CANCTRL0 is set, an interrupt
request is generated.
To clear this bit, first read it as a one, then write as a zero. Writing a one has no effect.
15
WAKEINT
Wake interrupt. The WAKEINT bit indicates that bus activity has been detected while the
TouCAN module is in low-power stop mode.
0 = No wake interrupt requested
1 = When the TouCAN is in low-power stop mode and a recessive to dominant transition is
detected on the CAN bus, this bit is set. If the WAKEMSK bit is set in CANMCR, an in-
terrupt request is generated.
Table 16-22 Transmit Bit Error Status
BITERR[1:0]
Bit Error Status
00
No transmit bit error
01
At least one bit sent as dominant was received as recessive
10
At least one bit sent as recessive was received as dominant
11
Not used
Table 16-23 Fault Confinement State Encoding
FCS[1:0]
Bus State
00
Error active
01
Error passive
1X
Bus off
IMASK —
Interrupt Mask Register
0x30 70A2, 0x30 74A2
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
IMASKH
IMASKL
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 16-24 IMASK Bit Descriptions
Bit(s)
Name
Description
0:7,
8:15
IMASKH,
IMASKL
IMASK contains two 8-bit fields, IMASKH and IMASKL. IMASK can be accessed with a 16-
bit read or write, and IMASKH and IMASKL can be accessed with byte reads or writes.
IMASK contains one interrupt mask bit per buffer. It allows the CPU to designate which buff-
ers will generate interrupts after successful transmission/reception. Setting a bit in IMASK
enables interrupt requests for the corresponding message buffer.
NOTE
: Bit 15 (LSB) corresponds to message buffer 0. Bit 0 (MSB) corresponds to mesage
buffer 15.
Table 16-21 ESTAT Bit Descriptions (Continued)
Bit(s)
Name
Description
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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