COM20020I3V-DZD-TR Standard Microsystems (SMSC), COM20020I3V-DZD-TR Datasheet - Page 32

• Manufacturer Part Number: COM20020I3V-DZD-TR
• Manufacturer: Standard Microsystems (SMSC)

Specifications of COM20020I3V-DZD-TR

• Number Of Transceivers: 1
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Compliant

Revision 12-06-06
BIT
4,3
1,0
6
5
2
Command
Chaining Enable
Transmit Enable
Extended
Timeout 1,2
Backplane
Sub Address 1,0
BIT NAME
CCHEN
TXEN
ET1, ET2
BACK-
PLANE
SUBAD
1,0
SYMBOL
DATASHEET
This bit, if high, enables the Command Chaining operation of
the device. Please refer to the Command Chaining section
for further details. A low level on this bit ensures software
compatibility with previous SMSC ARCNET devices.
When low, this bit disables transmissions by keeping
nPULSE1, nPULSE2 if in non-Backplane Mode, and nTXEN
pin inactive. When high, it enables the above signals to be
activated during transmissions. This bit defaults low upon
reset.
determined, and never disabled during normal operation.
Please refer to the Improved Diagnostics section for details
on evaluating network activity.
These bits allow the network to operate over longer distances
than the default maximum 2 miles by controlling the
Response, Idle, and Reconfiguration Times. All nodes should
be configured with the same timeout values for proper
network operation.
crystal oscillator, the bit combinations follow:
Note: These values are for 5Mbps and RCNTMR[1,0]=00.
Reconfiguration time is changed by the RCNTMR1 and
RCNTMR0 bits.
A logic "1" on this bit puts the device into Backplane Mode
signaling which is used for Open Drain and Differential Driver
interfaces.
These bits determine which register at address 07 may be
accessed. The combinations are as follows:
SUBAD1
See also the Sub Address Register.
0
0
1
1
ET2
0
0
1
1
This bit is typically enabled once the Node ID is
32
SUBAD0 Register
0
1
0
1
5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
ET1
0
1
0
1
For the COM20020I with a 20 MHz
Tentative ID
Node ID
Setup 1
Next ID
DESCRIPTION
Response
Time (μS)
596.6
298.4
149.2
37.4
Idle Time
(μS)
656
328
164
41
SMSC COM20020I 3.3V
Reconfig
Time
(mS)
840
840
840
420