SMSC COM20020 manual PIN Configuration

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controller optimized for use in industrial and automotive applications. Using an ARCNET protocol engine is the ideal solution for factory automation applications because it provides a token-passing protocol, a highly reliable and proven networking scheme, and a data rate of up to 2.5 Mbps when using the COM20020.

A token-passing protocol provides predictable response times because each network event occurs within a predetermined time interval, based upon the number of nodes on the

network. The deterministic nature of ARCNET is essential in mission critical applications. The integration of the 2Kx8 RAM buffer on-chip, the Command Chaining feature, the 2.5 Mbps maximum data rate, and the internal diagnostics make the COM20020 the highest performance industrial communications device available.

With only one COM20020 and one microcontroller, a complete communications node may be implemented.

ARCNET is a registered trademark of Datapoint Corporation

PIN CONFIGURATION

A0/nMUX

A1

A2/ALE

AD0

AD1

AD2

D3

D4

D5

D6

D7

VSS

 

 

 

24

 

1

 

 

 

 

 

23

 

 

 

 

2

 

 

 

22

 

 

 

 

 

3

 

 

 

 

 

21

 

4

 

 

 

20

 

 

 

 

5

 

 

 

 

 

19

 

 

 

 

6

 

 

 

18

 

 

7

 

 

 

 

 

17

 

8

 

 

 

16

 

 

 

 

 

9

 

 

 

 

 

15

 

10

 

 

 

14

 

 

 

 

11

 

 

 

13

 

 

 

 

12

 

 

 

 

 

 

 

 

VDD

nRD/nDS

nWR/DIR

nWR/DIR

nCS

nINTRnRD/nDS

nRESET IN

VDD

nTXEN

A0/nMUX

RXIN

A1

nPULSE2

A2/ALE

nPULSE1

AD0

XTAL2

XTAL1

 

 

 

 

 

 

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

S

 

 

 

 

 

 

N

 

 

S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

L

 

 

 

 

 

 

 

T

 

 

E

 

 

S

 

 

 

 

 

 

 

 

S

 

 

 

 

 

 

 

X

I

 

 

U

 

 

 

 

 

N

 

 

R

 

 

S

 

 

X

 

 

 

 

 

 

C

 

 

 

 

 

 

 

T

 

 

P

 

 

 

 

 

I

 

 

n

 

 

V

 

 

R

 

 

 

 

 

 

n

 

n

 

 

 

 

 

 

n

 

 

n

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

25

 

24

 

23

 

22

 

21

 

20

 

19

 

 

 

26

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

18

 

27

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

17

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

28

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

6

 

7

8

 

9

 

10

11

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

2

 

 

S

3

4

5

6

 

 

 

 

 

D

 

D

 

 

S

 

 

D

 

 

D

 

D

 

 

D

 

 

 

 

A

 

A

 

 

V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

nPULSE 1

XTAL2

XTAL1

VDD

VSS

N/C

D7

Packages: 24-Pin DIP or 28-Pin PLCC

Ordering Information:

COM20020 P

PACKAGE TYPE: P = Plastic, LJP = PLCC

TEMP RANGE: (Blank) = Commercial: 0°C to +70°C

I = Industrial: -40°C to +85°C

DEVICE TYPE: 20020 = Universal Local Area Network Controller (with 2K x 8 RAM)

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Contents General Description FeaturesTable of Contents PIN Configuration A1,A2/ALE Description of PIN FunctionsDIP PIN Plcc PIN Name Symbol Description Transmission Media InterfaceMiscellaneous Instead, it must be connected to XTAL1 with COM20020 Operation Data Rates Network ReconfigurationProtocol Description Network ProtocolExtended Timeout Function Broadcast MessagesResponse Time Invitations To Transmit Reconfiguration TimeIdle Time Line ProtocolData Packets AcknowledgementsNegative Acknowledgements System Description MULTIPLEXED, 8051-LIKE BUS Interface with RS-485 Interface Figure C Traditional Hybrid Interface Backplane ConfigurationCOM20020 Network Using RS-485 Differential Transceivers Programmable Txen Polarity Differential Driver ConfigurationInternal Block Diagram Cable Type Impedance AT 5MHZ Functional DescriptionAttenuation NominalRead Register Summary Write Tentative ID Register Internal RegistersInterrupt Mask Register IMR Data RegisterStatus Register Diagnostic Status RegisterCommand Register Next ID RegisterConfiguration Register Setup Register BIT BIT Name Symbol Description Dupid BIT BIT Name Symbol DescriptionData Command Description Address Pointer Low Register Address Pointer High RegisterReset Configuration RegisterCKP3 CKP2 CKP1 Sequential Access Operation Software Interface Sequential Access MemoryAccess Speed Internal RAMTransmit Sequence Selecting RAM Page SizeRAM Buffer Packet Configuration Page Receive Sequence Transmit Command Chaining Command ChainingReceive Command Chaining Internal Reset Logic Reset DetailsInitialization Sequence Improved DiagnosticsAbnormal Results Normal ResultsOscillator Operational Description Maximum Guaranteed RatingsDC Electrical Characteristics Parameter Symbol MIN TYP MAX Unit CommentXTAL1, XTAL2 Input Capacitance Multiplexed BUS, 68XX-LIKE Control Signals Read Cycle Timing DiagramsMultiplexed BUS, 80XX-LIKE Control Signals Read Cycle Multiplexed BUS, 68XX-LIKE Control Signals Write Cycle Multiplexed BUS, 80XX-LIKE Control Signals Write Cycle NON-MULTIPLEXED BUS, 80XX-LIKE Control Signals Read Cycle NON-MULTIPLEXED BUS, 68XX-LIKE Control Signals Read Cycle NON-MULTIPLEXED BUS, 80XX-LIKE Control Signals Write Cycle NON-MULTIPLEXED BUS, 68XX-LIKE Control Signals Write Cycle These signals are to and from the hybrid Normal Mode Transmit or Receive TimingNTXEN NPULSE1 TTL Input Timing on XTAL1 PIN 28-PIN Plcc Package Dimensions 24-PIN DIP Package Dimensions SECTION/FIGURE/ENTRY Correction Revised DateStandard Microsystems Corp
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