PXD20RM Datasheet, PDF (791/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Table 20-12. Error and Status Register (ESR) Field Descriptions (continued)
Field
Description
25
TXRX
26-27
FLT_CONF
29
BOFF_INT
30
ERR_INT
31
Current FlexCAN status (transmitting/receiving)
This bit indicates if FlexCAN is transmitting or receiving a message when the CAN bus is not in IDLE
state. This bit has no meaning when IDLE is asserted.
1 = FlexCAN is transmitting a message (IDLE=0)
0 = FlexCAN is receiving a message (IDLE=0)
Fault Confinement State
This 2-bit field indicates the Confinement State of the FlexCAN module, as shown in Table 20-13. If
the LOM bit in the Control Register is asserted, the FLT_CONF field will indicate “Error Passive.”
Since the Control Register is not affected by soft reset, the FLT_CONF field will not be affected by
soft reset if the LOM bit is asserted.
Bus Off’ Interrupt
This bit is set when FlexCAN enters ‘Bus Off’ state. If the corresponding mask bit in the Control
Register (BOFF_MSK) is set, an interrupt is generated to the CPU. This bit is cleared by writing it
to ‘1’. Writing ‘0’ has no effect.
1 = FlexCAN module entered ‘Bus Off’ state
0 = No such occurrence
Error Interrupt
This bit indicates that at least one of the Error Bits (bits 16-21) is set. If the corresponding mask bit
in the Control Register (ERR_MSK) is set, an interrupt is generated to the CPU. This bit is cleared
by writing it to ‘1’.Writing ‘0’ has no effect.
1 = Indicates setting of any Error Bit in the Error and Status Register
0 = No such occurrence
Reserved
Table 20-13. Fault Confinement State
Value
00
01
1X
Meaning
Error Active
Error Passive
Bus Off
20.4.4.9 Interrupt Mask Register High (IMRH)
This register allows any number of a range of 32 Message Buffer Interrupts to be enabled or disabled. It
contains one interrupt mask bit per buffer, enabling the CPU to determine which buffer generates an
interrupt after a successful transmission or reception (i.e. when the corresponding IFRH bit is set).
Freescale Semiconductor
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
20-25