Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK Scheda Tecnica
Codici prodotto
AT91SAM9X25-EK
950
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
41.9.20 CAN Message Data High Register
Name:
CAN_MDHx [x=0..7]
Address:
0xF8000218 (0)[0], 0xF8000238 (0)[1], 0xF8000258 (0)[2], 0xF8000278 (0)[3], 0xF8000298 (0)[4],
0xF80002B8 (0)[5], 0xF80002D8 (0)[6], 0xF80002F8 (0)[7], 0xF8004218 (1)[0], 0xF8004238 (1)[1], 0xF8004258 (1)[2],
0xF8004278 (1)[3], 0xF8004298 (1)[4], 0xF80042B8 (1)[5], 0xF80042D8 (1)[6], 0xF80042F8 (1)[7]
0xF8004278 (1)[3], 0xF8004298 (1)[4], 0xF80042B8 (1)[5], 0xF80042D8 (1)[6], 0xF80042F8 (1)[7]
Access:
Read-write
• MDH: Message Data High Value
When MRDY field is set in the CAN_MSRx register, the upper 32 bits of a received message are read or written by the software
application. Otherwise, the MDH value is locked by the CAN controller to send/receive a new message.
application. Otherwise, the MDH value is locked by the CAN controller to send/receive a new message.
In Receive with overwrite, the CAN controller may modify MDH value while the software application reads MDH and MDL regis-
ters. To check that MDH and MDL do not belong to different messages, the application has to check the MMI field in the
CAN_MSRx register. In this mode, the software application must re-read CAN_MDH and CAN_MDL, while the MMI bit in the
CAN_MSRx register is set.
ters. To check that MDH and MDL do not belong to different messages, the application has to check the MMI field in the
CAN_MSRx register. In this mode, the software application must re-read CAN_MDH and CAN_MDL, while the MMI bit in the
CAN_MSRx register is set.
Bytes are received/sent on the bus in the following order:
1.
CAN_MDL[7:0]
2.
CAN_MDL[15:8]
3.
CAN_MDL[23:16]
4.
CAN_MDL[31:24]
5.
CAN_MDH[7:0]
6.
CAN_MDH[15:8]
7.
CAN_MDH[23:16]
8.
CAN_MDH[31:24]
31
30
29
28
27
26
25
24
MDH
23
22
21
20
19
18
17
16
MDH
15
14
13
12
11
10
9
8
MDH
7
6
5
4
3
2
1
0
MDH