CR16MCS9VJE8 National Semiconductor, CR16MCS9VJE8 Datasheet - Page 102

• Manufacturer Part Number: CR16MCS9VJE8
• Description: 16-Bit Microcontroller IC
• Manufacturer: National Semiconductor

Specifications of CR16MCS9VJE8

• Controller Family/series: CR16X
• Core Size: 16 Bit
• Program Memory Size: 64K X 8 Flash
• Digital Ic Case Style: PQFP
• No. Of Pins: 80
• Mounting Type: Surface Mount
• Clock Frequency: 25MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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20.6.3
The transmission of a CAN message has to be executed as
follows (see also Figure65)
Writing TX_ONCE or TX_ONCE_RTR in the CNSTAT status
field will set the internal transmit request for the CR16CAN.
If a buffer is configured as TX_RTR and a remote frame is re-
ceived, the data contents of the addressed buffer will be
transmitted automatically without further CPU activity.
1. Configure CNSTAT status field as TX_NOT_ACTIVE. If
2. Load buffer identifier & data registers. (For remote
3. Configure CNSTAT status field to the desired value:
— TX_ONCE to trigger the transmission process of a sin-
— TX_ONCE_RTR to trigger the transmission of a single
— TX_RTR waits for a remote frame to trigger the trans-
the status is TX_BUSY, a previous transmit request is
still pending and the user has no access to the data con-
tents of the buffer. In that case the user may choose to
wait until the buffer becomes available again as shown.
Other options are to exit from the update routine until the
buffer has been transmitted with an interrupt generated,
or the transmission is aborted by an error.
frames the RTR bit of the identifier needs to be set and
loading data bytes can be omitted.)
gle frame.
data frame and then wait for a received remote frame
to trigger consecutive data frames.
mission of a data frame.
Transmit Procedure
102
Figure 65. Buffer Write Routine
TX_ONCE_RTR
TX_NOT_ACTIVE
write_buffer
TX_BUSYx?
write ID/data
TX_ONCE
TX_RTR
write
write
N
or
or
exit
Y
(see text)