TMC2074-NE SMSC, TMC2074-NE Datasheet - Page 55

• 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

Dual Mode CircLink™ Controller
Datasheet
2.12
2.12.1 Functions Provided by NST
SMSC TMC2074
NST Prescale
NSTPRE[2:0]
NST Prescale
NSTPRE[2:0]
000
001
010
011
100
101
110
111
Network Standard Time (NST)
Network standard time (NST) is a 16-bit free-running counter. Each node adjusts the time after receiving a
packet from the clock master node (CM node), ensuring that all nodes share the common standard time on
the network. This minimizes phase deviation among nodes within about 100 μs.
The NST prescaler pin (NSTPRE2, 0) is used to set the count speed of the NST. The following table lists
the relations among setting, resolution, and maximum time:
Automatic generation of packet with time stamp
Setting one (1) to the NSTSEND bit in the MODE register allows the last 2 bytes in a packet to be reserved
for the NST area, and the newest value of NST is automatically sent in these 2 bytes (nothing is written in
the sending buffer RAM).
In the case of the clock master node (described in a later section), the same operation is carried out
regardless of the NSTSEND value. The value is used as the time stamp of the packet and also used to
maintain synchronization of time on the network.
000
001
010
011
100
101
110
111
Prescale
Prescale
1:1024
1:2048
1:4096
1:1024
1:2048
1:4096
1:128
1:256
1:512
1:128
1:256
1:512
1:32
1:64
1:32
1:64
Resolution
Resolution
DATASHEET
102.4us
128.0us
12.8us
25.6us
51.2us
16.0us
32.0us
64.0us
0.8us
1.6us
3.2us
6.4us
1.0us
2.0us
4.0us
8.0us
40MHz Xtal
32MHz Xtal
Page 55
MAX Period
MAX Period
52.4ms
105ms
210ms
419ms
839ms
1.68s
3.36s
6.71s
0.07s
0.13s
0.26s
0.52s
1.05s
2.10s
4.19s
8.39s
Resolution
Resolution
102.4us
204.8us
128.0us
256.0us
12.8us
25.6us
51.2us
16.0us
32.0us
64.0us
1.6us
3.2us
6.4us
2.0us
4.0us
8.0us
20MHz Xtal
16MHz Xtal
Revision 0.2 (10-23-08)
MAX Period
MAX Period
105ms
210ms
419ms
839ms
13.42s
16.78s
1.68s
3.36s
6.71s
0.13s
0.26s
0.52s
1.05s
2.10s
4.19s
8.39s