COM20019I-DZD SMSC, COM20019I-DZD Datasheet - Page 32

• Manufacturer Part Number: COM20019I-DZD
• Description: IC CTRLR ARCNET 2KX8 RAM 28-PLCC
• Manufacturer: SMSC
• Series: ARCNETr

Specifications of COM20019I-DZD

• Controller Type: ARCNET Controller
• Interface: Differential
• Voltage - Supply: 4.5 V ~ 5.5 V
• Current - Supply: 20mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 638-1000-5

Rev. 09-25-07
4,3
2
1,0
7
6
5
4
BIT
BIT
Pulse1 Mode
Four NACKS
Reserved
Receive All
Extended
Timeout 1,2
Backplane
Sub Address 1,0
BIT NAME
BIT NAME
ET1, ET2
BACK-
PLANE
SUBAD
1,0
P1MODE
FOUR
NACKS
RCVALL
SYMBOL
SYMBOL
Table 6.10 - Setup 1 Register
DATASHEET
These bits allow the network to operate over longer
distances than the default maximum 32 miles by controlling
the Response, Idle, and Reconfiguration Times. All nodes
should be configured with the same timeout values for
proper network operation. For the COM20019I with a 20
MHz crystal oscillator, the bit combinations follow:
ET2
0
0
1
1
Note: These values are for 312.5 Kbps 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. This bit must be set to ‘1’ at the
COM20019I.
These bits determine which register at address 07 may be
accessed. The combinations are as follows:
SUBAD1
See also the Sub Address Register.
This bit determines the type of PULSE1 output driver used
in Backplane Mode. When high, a push/pull output is
used. When low, an open drain output is used. The
default is open drain.
This bit, when set, will cause the EXNACK bit in the
Diagnostic Status Register to set after four NACKs to Free
Buffer Enquiry are detected by the COM20019I. This bit,
when reset, will set the EXNACK bit after 128 NACKs to
Free Buffer Enquiry. The default is 128.
Do not set.
This bit, when set, allows the COM20019I to receive all
valid data packets on the network, regardless of their
destination ID. This mode can be used to implement a
network monitor with the transmitter on- or off-line. Note
that ACKs are only sent for packets received with a
destination ID equal to the COM20019I's programmed
node ID. This feature can be used to put the COM20019I
in a 'listen-only' mode, where the transmitter is disabled
and the COM20019I is not passing tokens. Defaults low.
0
0
1
1
Page 32
Cost Competitive ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
ET1
0
1
0
1
SUBAD0
0
1
0
1
DESCRIPTION
DESCRIPTION
Response
Time (mS)
9.548
4.774
2.387
0.597
Register
Tentative I
Node ID
Setup 1
Next ID
Idle Time
(mS)
10.496
5.248
2.624
0.656
Reconfig
Time (S)
13.44
13.44
13.44
6.72
SMSC COM20019I