XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 292

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

msCAN12 Controller
16.12.7 msCAN12 Transmitter Flag Register
Data Sheet
292
NOTE:
BOFFIE — Bus-Off Interrupt Enable Bit
OVRIE — Overrun Interrupt Enable Bit
RXFIE — Receiver Full Interrupt Enable Bit
The CRIER register is held in the reset state when the SFTRES bit in CMCR0 is
set.
The abort acknowledge flags are read only. The transmitter buffer empty flags are
read and clear only. A flag can be cleared by writing a 1 to the corresponding bit
position. Writing a 0 has no effect on the flag setting. Each transmitter buffer empty
flag has an associated interrupt enable bit in the CTCR register. A hard or soft reset
resets the register.
ABTAK2–ABTAK0 — Abort Acknowledge Flag
TXE2–TXE0 —Transmitter Buffer Empty Flag
This flag acknowledges that a message has been aborted due to a pending
abort request from the CPU. After a particular message buffer has been flagged
empty, this flag can be used by the application software to identify whether the
message has been aborted successfully or has been sent in the meantime. The
ABTAKx flag is cleared implicitly whenever the corresponding TXE flag is
cleared.
This flag indicates that the associated transmit message buffer is empty, thus
not scheduled for transmission. The CPU must handshake (clear) the flag after
a message has been set up in the transmit buffer and is due for transmission.
The msCAN12 sets the flag after the message has been sent successfully. The
flag is also set by the msCAN12 when the transmission request was aborted
Address: $0106
Reset:
Read:
Write:
0 = No interrupt is generated from this event.
1 = A bus-off event results in an error interrupt.
0 = No interrupt is generated from this event.
1 = An overrun event results in an error interrupt.
0 = No interrupt is generated from this event.
1 = A receive buffer full (successful message reception) event results in a
0 = The message has not been aborted; it has been sent.
1 = The message has been aborted.
Figure 16-22. msCAN12 Transmitter Flag Register (CTFLG)
receive interrupt.
Bit 7
0
0
= Unimplemented
ABTAK2
msCAN12 Controller
6
0
ABTAK1
5
0
ABTAK0
4
0
3
0
0
M68HC12B Family — Rev. 8.0
TXE2
2
1
TXE1
1
1
MOTOROLA
TXE0
Bit 0
1