mc68hc08qa24 Freescale Semiconductor, Inc, mc68hc08qa24 Datasheet - Page 377

• Manufacturer Part Number: mc68hc08qa24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

22.14.8 MSCAN08 Transmitter Control Register
MC68HC08QA24
Freescale Semiconductor
Address:
TXE2–TXE0 — Transmitter Empty Flag
ABTRQ2–ABTRQ0 — Abort Request Flags
Reset:
Read:
Write:
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 MSCAN08 will set the
flag after the message has been sent successfully. The flag also will
be set by the MSCAN08 when the transmission request was
successfully aborted due to a pending abort request (see
Transmit Buffer Priority
interrupt is pending while this flag is set.
A reset of this flag also will reset the abort acknowledge (ABTAK) and
the abort request (ABTRQ) flags of the particular buffer. See
22.14.8 MSCAN08 Transmitter Control
The CPU sets this flag to request that an already scheduled message
buffer (TXE = 0) be aborted. The MSCAN08 will grant the request
when the message is not already under transmission. When a
message is aborted the associated TXE and the abort acknowledge
flag (ABTAK) (see
Figure 22-21. CAN Transmitter Control Register (CTCR)
1 = The associated message buffer is empty (not scheduled).
0 = The associated message buffer is full (loaded with a message
$0507
Bit 7
due for transmission).
R
R
0
0
ABTRQ2 ABTRQ1 ABTRQ0
= Reserved
CAN Controller
6
0
22.14.7 MSCAN08 Transmitter Flag
5
0
Registers). If not masked, a receive
4
0
R
3
0
0
Register.
TXEIE2
2
0
TXEIE1
CAN Controller
1
0
Technical Data
Register)
22.13.5
TXEIE0
Bit 0
0
375