TMC2074-NE SMSC, TMC2074-NE Datasheet - Page 58

• 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

NOTE:
Revision 0.2 (10-23-08)
CKP[2:0]
000
001
010
011
100
101
Communication speed (Data rate) and phase error
The time difference becomes longer as communication speed becomes slower. The reason for this is
because some data processing in CircLink such as CRC check is dependent upon the data rate. The
relation between the transfer speed and time difference from CM to CS is listed as follows.
CircLink has an offset value built-in to absorb the phase error depending on communication speed.
Moreover, the offset value can be manually set at the higher threshold of the CARRY register.
Only automatic setup is available in the standalone mode and condition of NSTPRE2 = L(0).
OFSMOD (CARRY register: bit 15)
0: Automatic offset (default) 1: Manual offset
NSTOFS4 -0 (CARRY register: bit 12 to 8)
The offset value is selected among 0 to 31.
The actual offset time is “NST resolution x NSTOFS4-0”.
Unlock flag
Synchronization between the NST unlock flag in the CM node and the NST in any other node is tracked by
the NSTUNLOC signal in the INTSTA register. This flag can be used as an interrupt source. In the
standalone mode, this flag is output to nINTR pin.
0: Synchronous lock state, 1: Synchronous unlock state (default)
*About approval condition for Synchronous lock /unlock state
- Unlock to lock state (NSTUNLOC=0)
The difference between own NST and NST from CM node is within +/-2. And NST from CM node must be
received three times or more continuously, and all of those differences must be within +/-2.
- Lock to unlock state (NSTUNLOC=1)
The difference between own NST and NST from CM node is not within +/-2. Or NST from CM node must
be received three times or more continuously, and all of those differences are not within +/-2.
Notes : "CM --> CS Time Difference" does NOT include cable Propagation Delay.
62.5K (78.125K) bps
125K (156.25K) bps
Communication
250K (312.5K) bps
1.0M (1.25M) bps
500K (625K) bps
2.0M (2.5M) bps
Speed
16MHz( 20MHz ) XTAL
Time Difference
DATASHEET
CM --> CS
220 ( 176 ) us
440 ( 352 ) us
880 ( 704 ) us
27.5 ( 22 ) us
110 ( 88 ) us
55 ( 44 ) us
Page 58
125K (156.25K) bps
Communication
250K (312.5K) bps
1.0M (1.25M) bps
500K (625K) bps
4.0M (5.0M) bps
2.0M (2.5M) bps
Speed
32MHz( 40MHz ) XTAL
Dual Mode CircLink™ Controller
Time Difference
CM --> CS
220 ( 176 ) us
440 ( 352 ) us
13.8 ( 11 ) us
27.5 ( 22 ) us
110 ( 88 ) us
SMSC TMC2074
55 ( 44 ) us
Datasheet