mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 330

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

Freescale’s Controller Area Network (MSCANV1)
Read: Anytime
Write: Anytime when not in initialization mode
15.3.8
The CANTARQ register allows abort request of messages queued for transmission.
Read: Anytime
Write: Anytime when not in initialization mode
15-14
ABTRQ[2:0]
TXEIE[2:0]
Field
Field
2:0
2:0
Reset:
W
R
MSCAN Transmitter Message Abort Request Register (CANTARQ)
Transmitter Empty Interrupt Enable
0 No interrupt request is generated from this event.
1 A transmitter empty (transmit buffer available for transmission) event causes a transmitter empty interrupt
Abort Request — The CPU sets the ABTRQx bit to request that a scheduled message buffer (TXEx = 0) be
aborted. The MSCAN grants the request if the message has not already started transmission, or if the
transmission is not successful (lost arbitration or error). When a message is aborted, the associated TXE (see
Section 15.3.6, “MSCAN Transmitter Flag Register
Section 15.3.9, “MSCAN Transmitter Message Abort Acknowledge Register
interrupt occurs if enabled. The CPU cannot reset ABTRQx. ABTRQx is reset whenever the associated TXE flag
is set.
0 No abort request
1 Abort request pending
Figure 15-11. MSCAN Transmitter Message Abort Request Register (CANTARQ)
request. See
The CANTIER register is held in the reset state when the initialization mode
is active (INITRQ = 1 and INITAK = 1). This register is writable when not
in initialization mode (INITRQ = 0 and INITAK = 0).
The CANTARQ register is held in the reset state when the initialization
mode is active (INITRQ = 1 and INITAK = 1). This register is writable
when not in initialization mode (INITRQ = 0 and INITAK = 0).
0
0
7
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
= Unimplemented
Section 15.5.2.2, “Transmit
Table 15-13. CANTARQ Register Field Descriptions
Table 15-12. CANTIER Register Field Descriptions
6
0
0
0
0
5
Structures” for details.
NOTE
NOTE
4
0
0
Description
Description
(CANTFLG)”) and abort acknowledge flags (ABTAK, see
0
0
3
ABTRQ2
(CANTAAK)”) are set and a transmit
2
0
ABTRQ1
Freescale Semiconductor
0
1
ABTRQ0
0
0