upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 717

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

CAN Controller (CAN)
ID28
ID28
ID17
ID6
x
x
x
x
19.10.3 Mask function
Note
Note
ID27
ID27
ID16
ID5
0
0
x
x
It can be defined whether masking of the identifier that is set to a message
buffer is linked with another message buffer.
By using the mask function, the identifier of a message received from the CAN
bus can be compared with the identifier set to a message buffer in advance.
Regardless of whether the masked ID is set to 0 or 1, the received message
can be stored in the defined message buffer.
While the mask function is in effect, an identifier bit that is defined to be 1 by a
mask in the received message is not compared with the corresponding
identifier bit in the message buffer.
However, this comparison is performed for any bit whose value is defined as 0
by the mask.
For example, let us assume that all messages that have a standard-format ID,
in which bits ID27 to ID25 are 0 and bits ID24 and ID22 are 1, are to be stored
in message buffer 14. The procedure for this example is shown below.
<1> Identifier to be stored in message buffer
x = don’t care
<2> Identifier to be configured in message buffer 14 (example)
1.
2.
Preliminary User’s Manual U17566EE1V2UM00
ID26
ID26
ID15
ID4
0
0
x
x
ID with the ID27 to ID25 bits cleared to 0 and the ID24 and ID22 bits set to
1 is registered (initialized) to message buffer 14.
Message buffer 14 is set as a standard format identifier that is linked to
mask 1 (CnMCONF14.MT2 to CnMCONF14.MT0 bits are set to 010B).
(Using C0MIDL14 and C0MIDH14 registers)
ID25
ID25
ID14
ID3
0
0
x
x
ID24
ID24
ID13
ID2
1
1
x
x
ID23
ID23
ID12
ID1
x
x
x
x
ID22
ID22
ID11
ID0
1
1
x
x
ID21
ID21
ID10
x
x
x
ID20
ID20
ID9
x
x
x
ID19
ID19
ID8
x
x
x
Chapter 19
ID18
ID18
ID7
x
x
x
717