TMC2072-MD SMSC, TMC2072-MD Datasheet - Page 44

• Manufacturer Part Number: TMC2072-MD
• Description: Network Controller & Processor ICs Peripheral Mode CircLink Cntlr
• Manufacturer: SMSC

Specifications of TMC2072-MD

• Product: Controller Area Network (CAN)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.9.3
2.9.4
Revision 0.1 (06-07-07)
…
…
…
1 WARTC Clear Command
2 Release Interrupt Mask
3 Read Data
3 Read Data
3 Read Data
3 Read Data
3 Read Data
4 Read EC Status
5 Error processing
6 Interrupt Mask
CPU Side
Example of Receive Flow in Remote Buffer Mode
(RXMH/RXML REGISTER: When in RXM07 = 1)
CircLink is used as a simple data buffer such as "read data from the CircLink at any time".
After completing the receive of remote buffer mode, RRCV (Remote buffer receive end flag) in the EC
interrupts the status register (INTSTA) and changes from 0 to 1, permitting the flag to be an interrupt
source. This mode also monitors if a packet comes from applicable nodes within a certain period. If there is
a non-responsive node, the WARTERR flag changes from 0 to 1, permitting this change to be an interrupt
source. Refer to section 3.2.10 - INTSTA Register: EC Interrupt Status.
Warning Timer (WT) at Remote Buffer Receive
CircLink checks the logical AND RXF flags of all pages that are set to remote buffer mode. A result of 1
during a cycle , indicates a normal state, in which there is no silent node on the network. In this case the
object flags are cleared after a certain period of time (see table below).
Conversely, if the result retains a 0, the condition is not in a normal state, and WATERR in the EC interrupt
status register changes from 0 to 1. This condition will generate an interrupt..
This function is initialized by writing a warning timer clear command into the EC command register. The
monitoring time is set by the warning timer resolution setup pins WPRE [2:0] and WARTC3-0 in the Carry
Selection register.
Actually, the warning timer clear command only clears WATERR flag. The Warning timer function starts
automatically after releasing the software reset. So some initial settings for this function are set before
releasing the software reset.
(See following steps)
Step-1: Turn on software reset (RESET bit = 1 in COMR6 register)
…
…
…
DATASHEET
Page 44
Interrupt occure
Each time packet
comes automatic
WARTERR = 1
TMC2074/72
RXFn = X->0
(NID=n)
receive
…
…
Peripheral Mode CircLink™ Controller
LAN Side
SMSC TMC2072
Datasheet