FPGA可编程逻辑器件芯片10M08SFU169C8G中文规格书

Figure 27-47: CAN_OPSS2 Register Diagram
Table 27-42: CAN_OPSS2 Register Fields
Bit No. (Access)
Bit Name
15:0 MB (R/W)
Description/Enumeration Mailbox n Overwrite Protection Enable.
2 EP (R/NW)
CAN Error Passive Mode. The CAN_STAT.EP bit indicates whether the CAN is in error passive mode.
0 TXECNT and RXECNT Below 128
1 TXECNT or RXECNT Above EP Level
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0000000000000000
MB (R/W) Mailbox n Overwrite Protection Enable
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 0000000000000000
Table 27-46: CAN_RML2 Register Fields
Bit No. (Access)
Bit Name
7:0 MB (R/NW)
Mailbox n Message Lost.
Description/Enumeration
ADSP-BF70x Blackfin+ Processor Hardware Reference
Bit Name
Description/Enumeration
6 CSA (R/NW)
CAN Suspend Mode Acknowledge. The CAN_STAT.CSA bit indicates whether the CAN is in suspend mode.
0 Not in Suspend Mode
0 WT (R/NW)
CAN Transmit Warning Flag.
The CAN_STAT.WT bit indicates whether the CAN detected a transmit warຫໍສະໝຸດ ing flag condition.
0 TXECNT Below Limit
1 TXECNT at Limit
1 Suspend mode
3 EBO (R/NW)
CAN Error Bus Off Mode. The CAN_STAT.EBO bit indicates whether the CAN is in error bus off mode.
0 TXECNT Below 256
1 TXECNT Above Bus Off Limit
1 WR (R/NW)
CAN Receive Warning Flag.
The CAN_STAT.WR bit indicates whether the CAN has detected a receive warning flag condition.
0 RXECNT Below Limit
1 RXECNT at Limit
ADSP-BF70x Blackfin+ Processor Hardware Reference
ADSP-BF70x CAN Register Descriptions
Receive Message Lost 2 Register
The CAN_RML2 register indicates when a message is lost---due to a message coming while there is pending data (corresponding CAN_RMP2 bit set) and overwrite protection is disabled (CAN_OPSS2 bit cleared)---for mailboxes 16 (bit 0) through 23 (bit 7). Each bit in this register indicates the message lost status for the corresponding mailbox when set (=1). Bits 8 through 15 are reserved, as the corresponding mailboxes (24 through 31) are transmit-only mailboxes.
ADSP-BF70x Blackfin+ Processor Hardware Reference
ADSP-BF70x CAN Register Descriptions
Table 27-49: CAN_STAT Register Fields (Continued)
Bit No. (Access)
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0000000000000000
MB (R) Mailbox n Message Lost
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 0000000000000000
Figure 27-51: CAN_RML2 Register Diagram
ADSP-BF70x CAN Register Descriptions
Overwrite Protection/Single Shot Transmission 2 Register
The CAN_OPSS2 register enables overwrite protection for mailboxes 16 (bit 0) through 31 (bit 15). Each bit in this register enables overwrite protection for the corresponding mailbox when set (=1). Note that enabling this bit affects transmit and receive operations for mailboxes. For more information about remote overwrite protection, see the detailed feature description in the CAN Functional Description section. For more information about how this feature affects transmit and receive operations, see the CAN Operating Modes sections, describing transmit and receive operations.