TMC2074-NE SMSC, TMC2074-NE Datasheet - Page 62

• Manufacturer Part Number: TMC2074-NE
• Description: Network Controller & Processor ICs Standalone Mode CircLink Cntlr
• Manufacturer: SMSC

Specifications of TMC2074-NE

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

2.13
2.14
Revision 0.2 (10-23-08)
NST Supplements
Setting NST send mode nullifies the last two-byte areas in the sending buffer. That is, the NST value is not
written in the last two-byte areas. The NST value is directly loaded to the parallel-to-serial conversion
register for transmit without using the buffer area RAM (not stored in a buffer). Therefore, the CircLink
always sends the newest NST value.
In addition, the clock master node (CM) sends NST, regardless of the NST send mode (CM node forcibly
enters the NST sending mode).
The NST value to be sent is the value immediately before the last two bytes are sent to the parallel to
serial conversion register. In the other words, the NST value shows the time immediately after sending the
third data from the last.
From the viewpoint of the receiver, the NST value is stored at the last two bytes area in the buffer page
corresponding to the SID value of the received packet. If the SID value in the receive packet is the ID of
the clock master node, its NST value is automatically adjusted. The received NST becomes available for
time adjustment at the time when ending “0” becomes OK after CRC error check completion.
CMI Modem
Refer to Appendix A - CMI Modem at the end of this document.
HUB Function
CircLink integrates a 3-port HUB function to expand the network. The HUB function enables conversion of
different communication media among twist-pair cable, fiber optics, and the like. In addition, the HUB
function expands the connection node number and cable length limitations caused by transceiver
performance limitations.
The HUB function is enabled by nHUBON pin. Among three ports, one is used internally for the connection
to CircLink main unit and the remaining two are used as external ports.
DATASHEET
Page 62
Dual Mode CircLink™ Controller
SMSC TMC2074
Datasheet