PCM-2074 EVB User Manual - SMSCww1.microchip.com/downloads/en/DeviceDoc/pcm2074user.pdf · PCM-2074 EVB User Manual Revision 1.0 (03-31-06) USER MANUAL SMSC PCM-2074 2 1 General Description

SMSC PCM-2074

PCM-2074 EVB User Manual

USER MANUAL Revision 1.0 (03-31-06)


1 General DescriptionThe PCM-2074 allows users to evaluate the CircLinkTM protocol using a TMC2074 CircLinkTM

controller configured for operation in peripheral mode. The PCM-2074 consists of two boardsconnected by a 14-pin ribbon cable, which together act as a CircLinkTM Host node, and a softwaredriver. The maximum communication rate of the two-board-set is 5 Mbps.

The PCM-2074 Main Board contains the following:

On-board TMC2074, configured to operate in peripheral mode

Type II PCMCIA interface using ZiLOG Z1601720ASC

One socket for GPIO connectors

Note: The PCMCIA connection does not support CardBus or ExpressCardTM. It also does notsupport the Suspend/Resume functions.

The PCM-2074 RS485 Board contains:

An RS485 transceiver

Two RJ-11 modular jacks

Note: The RJ-11 jacks are not configured to support the CircLinkTM Hub function.

The software driver supplied with the PCM-2074 supports Windows 2000 and Windows XP and comeswith a support library.

Note: Please download the latest version of the driver from SMSC’s website, along with the latestversion of this manual and other application notes relating to SMSC’s CircLinkTM products

Revision 1.0 (03-31-06) USER MANUAL SMSC PCM-2074

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2 Connectors and LEDsThe photograph below shows important features of the Main Board of the PCM-2074.

Figure 2.1 The PCM-2074 Main Board

CN1

CN3

CN4

D2D1

CN1

CN2

D3

SMSC PCM-2074 USER MANUAL Revision 1.0 (03-31-06)

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Table 2.1 Table of Connectors and LEDs for the PCM-2074 Main Board

DESIGNATOR SILKSCREEN DESCRIPTION

CN1 - 14-pin right-angle connector, attaches to CN1 of the RS485 Board via a flat ribbon cable

CN2 - Through-holes for mounting a connector for the GPIO signals

D3 CS LED turns on when the host card is accessed via the PCMCIA interface

Table 2.2 Table of Connectors and LEDs for the PCM-2074 RS485 Board

DESIGNATOR SILKSCREEN DESCRIPTION

CN1 - 14-pin straight connector, attaches to CN1 of the Main Board via a flat ribbon cable

CN3, CN4 - Two Modular RJ-11 jacks, electrically connected. Install 125 ohm termination resistor across one of these connectors.

D1 PWR Turns on when power is supplied via CN1

D2 TXEN Turns on while transmitting.


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3 EVB Configuration (Jumper Settings)The illustrations below shows the location of jumpers and switches on the two boards.

Note: CN2 and SW1 on the Main Board are not populated.

Figure 3.1 Location of Jumpers and Switches on the Main Board

Figure 3.2 Location of Jumpers and Switches on the RS485 Board


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3.1 Configuring the Main Board

Table 3.1 and Table 3.2 below how to configure the Main Board using SW2.

3.2 Configuring the RS485 Board

Table 3.3 and Table 3.4 below show how to configure the RS485 Board.

Note: The Hub function is not used on the PCM-2074; SW1-2 should always be set in the defaultposition.

Table 3.1 SW2 (Main Board) Configuration Settings

POS. NAME DESCRIPTIONON(=0)

OFF(=1) DEFAULT

8 MCKSEL1 Input clock frequency select, Bit 1 (MSB) See Table 3.2 below

10b(20 Mhz)

7 MCKSEL0 Input clock frequency select, Bit 0 (LSB)

6 W16 Data Bus Width 8 16 8

5 WPRE1 Warning Timer 1, Bit 1 (MSB) Refer to TMC-2074

Datasheet

11b

4 WPRE0 Warning Timer, Bit 0 (LSB)

3 NSTPRE2 NST Resolution, Bit 2 (MSB) Refer to TMC-2074

Datasheet

000b

2 NSTPRE1 NST Resolution, Bit 1

1 NSTPRE0 NST Resolution, Bit 0 (LSB)

Table 3.2 Input Clock Configuration

MCKSEL1 MCKSEL0 CLOCK FREQ. MAX BAUD RATE

1 1 40 Mhz 5 Mbps

1 0 20 Mhz 2.5 Mbps

0 1 10 Mhz 1.25 Mbps

0 0 Reserved

Table 3.3 SW1 (RS485 Board) Configuration Settings

POS. NAME DESCRIPTION ON OFF DEFAULT

SW1-2 nHubON Enables Hub Mode Hub* No Hub No Hub

SW1-1 nCMIBYP Selects CMI or RZ mode RZ CMI CMI

Table 3.4 JP1, JP2 (RS485 Board) Configuration Settings

POS. NAME DESCRIPTION SHORT OPEN DEFAULT

JP1, JP2 (Offset Resistor)

Connects or disconnects Offset Resistors; both jumpers must be set the same way

Connected Dis-connected

Connected


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4 I/O ConnectorsThe Main Board has two connectors - CN1 and CN2 - to allow for input/output signals. CN1 comesmounted with a 14-pin connector, which is used to attach the RS485 Board using a ribbon cable. CN2,which has no connector attached, can be used for an optional GPIO (General Input/Output) connector.

Note: When using either connector, please adhere to the electrical limits specified in the TMC2074datasheet.

Table 4.1 below shows the pin-out for the CN1 connector on the Main Board. It also shows the pin-outfor the CN1 connector on the RS485 Board, except that all locations noted as Inputs change to Outputsand all locations noted as Outputs change to Inputs.

The pin-out for CN2 on the Main Board is shown in Table 4.2 below.

Table 4.1 Pin Assignments for CN1

Pin No. Attribute Name Pin No. Attribute Name

1 P VDD (+5V) 1 2 P VDD (+5V) 1

3 I nCMIBYP2 4 I nHUBON2

5 O TXEN2 6 P GND

7 I RXIN2 8 P GND

9 O TXD2 10 P GND

11 I RXIN22 12 P GND

13 O TXEN22 14 I TXENPOL2

Legend: P = Power/Ground; O = Output, I = Input, N/C - No Connection

Notes:1) Allowable current is 200mA or less;2) All Input and Output signals are buffered by a TC74VHCT244 and have 10k-ohm pull-up resistors connected.

Table 4.2 Pin Assignments for CN2

Pin No. Attribute Name Pin No. Attribute Name

1 P VDD (+5V)1 2 B GPIO73

3 B GPIO63 4 B GPIO53



9 B GPIO03 10 P GND

11 I nNSTCOUT3 12 O nRST2

Legend: P = Power/Ground; O = Output, I = Input, B - Bi-directional

Notes:1) Allowable current is 100mA or less;2) nRST is an active-low, reset output signal, and is buffered by a TC74VHCT08.3) GPIO(7:0) and nNSTCOUT connect directly to the TMC2074, with no additional buffering.


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5 ResetThe Main Board provides a power-on reset signal which is driven by an MB3771 integrated circuit.This circuit asserts the power-on reset signal when the Main Board is inserted into a PCMCIA slot, orwhen the PC it is attached to is powered on. A second reset signal is provided by the ZilogZ1601720ASC PCMCIA interface; this signal will reset the TMC2074 when asserted; it is also providedto the CN2 connector.

6 Monitoring the CMI Decode SignalWhen the Hub Function is disable, the CMI decoded signal (an RZ-coded signal) can be monitored onthe TP4 test point connection on the RS485 Board. Note that TP4 is not mounted.

7 Mechanical Specifications

Note: Each dimension represents a design value. Units are in mm.

Figure 7.1 Mechanical Specification for the Main Board

47 54

85.6

107


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Note: Each dimension represents a design value. Units are in mm.

8 Operating Conditions

9 Connecting Twisted Pair Cables to the RJ11 ConnectorsThe PCM-2074 provides two modular RJ11 jacks for connection to twisted pair cables, which need tobe supplied by the user. These cables should have a characteristic impedance of 125 ohms, in orderto match the impedance built into the board. Each end of the twisted pair cable should have a 125-ohm termination resistor attached.

Recommended cables and terminators:

Single wire type 125 ohm twisted pair cable (ARC-Cab/125T) from SMSC Japan

125Ω terminator (ARC-Term/125T) from SMSC Japan

For recommendations on the maximum cable-length, minimum node-spacing, and maximum numberof nodes, refer to the TMC2074 data sheet.

Figure 7.2 Mechanical Specification for the RS485 Board

Table 8.1 Operating Conditions

PARAMETER SPECIFICATION

Supply Voltage +5V +/- 5%

Current Consumption 500 mA

Temperature Range 10 to 45C, no condensation

47

47

2.6


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9.1 Point-to-point Connection

Connect two evaluation boards as shown below. Attach a termination resistor to both ends.

9.2 Bus Connection

Connect three or more EVBs as shown below. Place termination resistors at each end of the network.

Note: In addition to the termination resistors, the Offset Resistors must be connected or disconnecteddepending on the location. Refer to Section 9.3 for more details.

Figure 9.1 Point-to-Point Twisted Pair Connection

Figure 9.2 Bus Connection for 3 or more Nodes

Offset Resistors: Connected

Evaluation Board 1


Evaluation Board 1

Termination Resistor

Termination Resistor Twisted Pair Cable

Twisted Pair Cable


Evaluation Board 1

Offset Resistors:Disconnected

Evaluation Board 2


Evaluation Board 3

Termination Resistor

Termination Resistor Twisted Pair Cable


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9.3 Offset Resistors

The function of the offset resistors is to prevent the differential voltage on the twisted pair cable, whichis the voltage between the positive signal and the negative signal, from going to zero during idleperiods when nothing is driving the line. To maintain stable operation, the RS485 transceivers requirea differential voltage of generally at least 200mV.

The offset resistors, which operate as a pair, supply this differential. One Offset Resistor biases thepositive signal toward Vcc, while the other biases the negative signal toward ground. The configurationof the offset resistors within a CircLink node depends on how that node is connected within a network.The offset resistors should be installed on the end nodes of a network and should be removed ordisabled on the middle nodes of a network containing three or more nodes. This is shown in Figure 9.3below. (In the PCM-2074, the offset resistors are configured using JP1 and JP2.).

Figure 9.3 Offset Resistors

Offset Resistor Configurations: - Connect offset resistors on end-nodes - Remove or disconnect offset resistors on middle nodes

CircLink Controller

D R DR DR D R

Offset

Transmission line: positive

Transmission line: negative

RS485 IC

Remove offset resistors on EVBs located in the middle of the bus .

Termination resistor

Termination resistor

RS485 IC

RS485 IC

RS485 IC

CircLink Controller CircLink Controller CircLink Controller

OffsetOffset Offset


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9.3.1 Calculating the Value of the Offset Resistors

The discussion explains how the Offset Resistor values are calculated, and refers to Figure 9.4.

In order to simplify the following discussion, assume the sink and source currents are zero (IA = IB = 0).

The voltage VAB between node A and B of the Receiver is:

Since VTH, the threshold voltage, ranges from -0.2V to +0.2V, and VAB > | VTH |, we can write anequation for Rl as follows:

However, we must guarantee that under worst-case conditions, the differential voltage exceeds therequired threshold voltage with some margin. These conditions, which occur when Vcc and Rt are attheir minimum values set a maximum value for Rl. The equation for the worst-case can be written asfollows:

For the worst case conditions, we assume that VCC(min) = 4.75V, that Rt(min) = 124 x 0.95 = 117.8Ω,and that the threshold margin is 0.05V, therefore VTH(max)=0.25V. Putting these together, we get:,

Therefore, Rl (nominal) = (1060.2 / 1.05) = 1009.7 Ω

To summarize, Rl (nominal)= 1.0KΩ when Rt (nominal) = 124Ω, the threshold margin is .05V, and allresistors have 5% tolerances. Rl changes with the threshold margin. For a threshold margin of 0.01V,Rl = 1.2kΩ; for a margin of 0.1V, Rl = 820Ω.

Since the actual IA and IB are not equal to 0, VAB may be less than 0.2V. Further tuning of the resistorvalues may be required. To do this, measure the voltage between the receiver inputs (VAB) during anidle period using a digital voltmeter or oscilloscope.

Figure 9.4 Offset Resistor Value Calculation

D

DE

R

A

B

Vcc

GNDR1

RS485

R1 IA

The transmission line side is in an open, or floating state.

Rt

IB

Receiver portion

R

Rt x (Vcc)(2 x Rl) +Rt

VAB =

Rt x (Vcc - VTH)2 x VTH

Rl=

Rt(min) x (Vcc(min)- VTH(max))2 x VTH(max)Rl (max)=

117.8 x (4.75 - 0.25)2 x 0.25Rl (max)= =1060.2Ω


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9.4 RJ11 Pin Out

As shown in the figure above, only the two middle pins are used regardless of the number of pinsavailable. The pin just to the left of the middle is always positive (L+) and the pin just to the right ofthe middle is always negative (L-).

9.5 Routing to Modular Jack Connectors

Figure 9.5 Pin Out of an RJ-11 Modular Jack (Front View)

Figure 9.6 Routing to Modular Jack Connectors

4 Pin Type 6 Pin Type

Polarity

Pin Number

CN4 Modular jack connector

1 2 3 4

CN3 Modular jack connector1

2 3 4

L+ L-


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10 Transceiver ImplementationThe use of a non-isolated RS485 transceiver (the method used by the PCM-2074) is shown in thefigure below.:

For other transceiver implementations, refer to the CircLink Application Notes on the SMSC website.

11 Using the PCM-2074 with a Desktop PC To use the PCM-2074 evaluation board in the PCI slot of a desktop PC, please use a general-purposeconversion adaptor between the PCI slot and the PCM-2074 PCMCIA connector, such as the P111from Elan Digital Systems (website: www.elandigitalsystems.com). Note that there is no guarantee ofoperation or technical support provided by SMSC for this application.

Figure 10.1 Non-Isolated RS485 Transceiver

DI

DE

RE

A

B

RS-485 Transceive rLTC1485

TXEN

TXD

RXIN

L+

GND

1K

1K

Vcc (+5V)

Drv

Rcv

GND

R

L-


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12 Care and Usage Information

12.1 Precautions for Handling and Storage1. For proper operation, environmental and power supply limitation requirements must be adhered to.

2. Do not expose the PCM-2074 to chemicals or to liquids, such as water or oil, or to moisture orvapor during handling or storage. Such exposure may result in electrical shock, short circuits,damage to the PCM-2074, or fire.

3. Use and store the PCM-2074 on a stable, level surface, and avoid mechanical vibration or shock.

4. Do not subject the PCM-2074 to direct sunlight or excessive heat. Exposing the board to excessiveheat during use may damage it. Exposing the board to direct sunlight may cause damage orwarpage.

5. Do not use or store boards in dusty places.

6. Avoid using the PCM-2074 near TVs, radio receivers, cordless phones or similar devises. ThePCM-2074 may cause Electro-Magnetic Interference with these devices.

7. Do not use or store the PCM-2074 near equipment that generates strong electro-magnetic fields.Exposure to excessive Electro-magnetic fields may damage the board.

8. Do not put heavy loads on top of the PCM-2074 as this may damage it.

9. Avoid exposing the PCM-2074 to exogenous material such as metal particles. These may causeshort circuits and fire.

12.2 PC Installation Procedure1. Confirm that all jumpers and dip switches on both the Main Board and the RS485 Board are set

correctly.

2. Attach the RS485 Board to the Main Board using the ribbon cable, then insert the Main Board intoa PCMCIA slot, avoiding excessive force and aligning the card and slot correctly.

3. Avoid inserting or removing the RS485 Board during the power-on state.

4. Avoid excess stress on the ribbon cable connecting the Main Board to the RS485 Board.

5. Be sure not to exceed current consumption limits when providing power via CN1 or CN2.

6. Confirm correct operation of the evaluation board.

12.3 De-Installation Procedure1. Power off the system before removing boards or connectors to prevent damage.

2. Avoid excessive force when removing cables, boards, sockets or devices to avoid damaging them.

12.4 Miscellaneous Warnings

Attaching the PCM-2074 to a non-SMSC authorized fixture or PC may cause the following failures.

The PC may not function correctly.

The board does not work or exhibits intermittent failures.

The board causes damage to either the PC or other peripherals.

If there is a possibility that adjacent boards may contact each other, insert an insulator between themto avoid electric contact which may cause a defect in the board, system or peripherals, electric shock,or fire.


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Copyright © 2006 SMSC or its subsidiaries. All rights reserved.

Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient forconstruction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies.SMSC reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licensesunder any patent rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the mostrecently dated version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSCproducts are not designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injuryor severe property damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com.SMSC is a registered trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders. SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISINGFROM ANY COURSE OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION,WHETHER BASED ON CONTRACT; TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC HAS BEEN ADVISED OF THEPOSSIBILITY OF SUCH DAMAGES.

Revision 1.0 (03-31-06) 16 SMSC SMSC PCM-2074USER MANUAL

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PCM-2074 EVB User Manual - SMSCww1.microchip.com/downloads/en/DeviceDoc/pcm2074user.pdf · PCM-2074 EVB User Manual Revision 1.0 (03-31-06) USER MANUAL SMSC PCM-2074 2 1 General Description