PCM-2074 EVB User Manual

Transcription

1 SMSC PCM-2074 USER MANUAL Revision 1.0 ( )

2 1 General Description The PCM-2074 allows users to evaluate the CircLink TM protocol using a TMC2074 CircLink TM controller configured for operation in peripheral mode. The PCM-2074 consists of two boards connected by a 14-pin ribbon cable, which together act as a CircLink TM Host node, and a software driver. 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 Z ASC One socket for GPIO connectors The PCMCIA connection does not support CardBus or ExpressCard TM. It also does not support the Suspend/Resume functions. The PCM-2074 RS485 Board contains: An RS485 transceiver Two RJ-11 modular jacks The RJ-11 jacks are not configured to support the CircLink TM Hub function. The software driver supplied with the PCM-2074 supports Windows 2000 and Windows XP and comes with a support library. Please download the latest version of the driver from SMSC s website, along with the latest version of this manual and other application notes relating to SMSC s CircLink TM products Revision 1.0 ( ) USER MANUAL SMSC PCM

3 2 Connectors and LEDs The photograph below shows important features of the Main Board of the PCM D3 CN1 CN2 CN4 CN1 CN3 D1 D2 Figure 2.1 The PCM-2074 Main Board SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 3

4 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. Revision 1.0 ( ) USER MANUAL SMSC PCM

5 3 EVB Configuration (Jumper Settings) The illustrations below shows the location of jumpers and switches on the two boards. 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 SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 5

6 3.1 Configuring the Main Board Table 3.1 and Table 3.2 below how to configure the Main Board using SW2. Table 3.1 SW2 (Main Board) Configuration Settings POS. NAME DESCRIPTION ON (=0) OFF (=1) DEFAULT 8 MCKSEL1 Input clock frequency select, Bit 1 (MSB) See Table 3.2 below 7 MCKSEL0 Input clock frequency select, Bit 0 (LSB) 10b (20 Mhz) 6 W16 Data Bus Width WPRE1 Warning Timer 1, Bit 1 (MSB) Refer to TMC WPRE0 Warning Timer, Bit 0 (LSB) Datasheet 3 NSTPRE2 NST Resolution, Bit 2 (MSB) Refer to TMC NSTPRE1 NST Resolution, Bit 1 Datasheet 11b 000b 1 NSTPRE0 NST Resolution, Bit 0 (LSB) Table 3.2 Input Clock Configuration MCKSEL1 MCKSEL0 CLOCK FREQ. MAX BAUD RATE Mhz 5 Mbps Mhz 2.5 Mbps Mhz 1.25 Mbps 0 0 Reserved 3.2 Configuring the RS485 Board Table 3.3 and Table 3.4 below show how to configure the RS485 Board. 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 The Hub function is not used on the PCM-2074; SW1-2 should always be set in the default position. 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 Disconnected Connected Revision 1.0 ( ) USER MANUAL SMSC PCM

7 4 I/O Connectors The Main Board has two connectors - CN1 and CN2 - to allow for input/output signals. CN1 comes mounted 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. When using either connector, please adhere to the electrical limits specified in the TMC2074 datasheet. Table 4.1 below shows the pin-out for the CN1 connector on the Main Board. It also shows the pin-out for the CN1 connector on the RS485 Board, except that all locations noted as Inputs change to Outputs and all locations noted as Outputs change to Inputs. 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 ncmibyp 2 4 I nhubon 2 5 O TXEN 2 6 P GND 7 I RXIN 2 8 P GND 9 O TXD 2 10 P GND 11 I RXIN P GND 13 O TXEN I TXENPOL 2 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. The pin-out for CN2 on the Main Board is shown in Table 4.2 below. Table 4.2 Pin Assignments for CN2 Pin No. Attribute Name Pin No. Attribute Name 1 P VDD (+5V) 1 2 B GPIO7 3 3 B GPIO6 3 4 B GPIO5 3 5 B GPIO4 3 6 B GPIO3 3 7 B GPIO2 3 8 B GPIO1 3 9 B GPIO P GND 11 I nnstcout 3 12 O nrst 2 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. SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 7

8 5 Reset The 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, or when the PC it is attached to is powered on. A second reset signal is provided by the Zilog Z ASC PCMCIA interface; this signal will reset the TMC2074 when asserted; it is also provided to the CN2 connector. 6 Monitoring the CMI Decode Signal When the Hub Function is disable, the CMI decoded signal (an RZ-coded signal) can be monitored on the TP4 test point connection on the RS485 Board. Note that TP4 is not mounted. 7 Mechanical Specifications Figure 7.1 Mechanical Specification for the Main Board Each dimension represents a design value. Units are in mm. Revision 1.0 ( ) USER MANUAL SMSC PCM

9 Figure 7.2 Mechanical Specification for the RS485 Board Each dimension represents a design value. Units are in mm. 8 Operating Conditions Table 8.1 Operating Conditions PARAMETER SPECIFICATION Supply Voltage +5V +/- 5% Current Consumption Temperature Range 500 ma 10 to 45C, no condensation 9 Connecting Twisted Pair Cables to the RJ11 Connectors The PCM-2074 provides two modular RJ11 jacks for connection to twisted pair cables, which need to be supplied by the user. These cables should have a characteristic impedance of 125 ohms, in order to 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 number of nodes, refer to the TMC2074 data sheet. SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 9

10 9.1 Point-to-point Connection Connect two evaluation boards as shown below. Attach a termination resistor to both ends. Evaluation Board 1 Evaluation Board 1 Offset Resistors: Connected Offset Resistors: Connected Termination Resistor Twisted Pair Cable Termination Resistor 9.2 Bus Connection Figure 9.1 Point-to-Point Twisted Pair Connection Connect three or more EVBs as shown below. Place termination resistors at each end of the network. Evaluation Board 1 Offset Resistors: Connected Evaluation Board 2 Offset Resistors: Disconnected Evaluation Board 3 Offset Resistors: Connected Termination Resistor Twisted Pair Cable Twisted Pair Cable Termination Resistor Figure 9.2 Bus Connection for 3 or more Nodes In addition to the termination resistors, the Offset Resistors must be connected or disconnected depending on the location. Refer to Section 9.3 for more details. Revision 1.0 ( ) USER MANUAL SMSC PCM

11 9.3 Offset Resistors The function of the offset resistors is to prevent the differential voltage on the twisted pair cable, which is the voltage between the positive signal and the negative signal, from going to zero during idle periods when nothing is driving the line. To maintain stable operation, the RS485 transceivers require a differential voltage of generally at least 200mV. The offset resistors, which operate as a pair, supply this differential. One Offset Resistor biases the positive signal toward Vcc, while the other biases the negative signal toward ground. The configuration of 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 or disabled on the middle nodes of a network containing three or more nodes. This is shown in Figure 9.3 below. (In the PCM-2074, the offset resistors are configured using JP1 and JP2.). Termination resistor Transmission line: positive Transmission line: negative Termination resistor Offset Offset Offset Offset RS485 IC R D RS485 IC R D RS485 IC R D RS485 IC R D CircLink Controller CircLink Controller CircLink Controller CircLink Controller Remove offset resistors on EVBs located in the middle of the bus. Offset Resistor Configurations: - Connect offset resistors on end-nodes - Remove or disconnect offset resistors on middle nodes Figure 9.3 Offset Resistors SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 11

12 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. Vcc R DE D R A B IA IB R 1 R t R 1 GND The transmission line side is in an open, or floating state. Receiver portion RS485 Figure 9.4 Offset Resistor Value Calculation In order to simplify the following discussion, assume the sink and source currents are zero (I A = I B = 0). R t x (V cc ) The voltage V AB between node A and B of the Receiver is: V AB = (2 x R l ) +R t Since V TH, the threshold voltage, ranges from -0.2V to +0.2V, and V AB > V TH, we can write an equation for R l as follows: R t x (V cc - V TH ) R l = 2 x V TH However, we must guarantee that under worst-case conditions, the differential voltage exceeds the required threshold voltage with some margin. These conditions, which occur when V cc and R t are at their minimum values set a maximum value for R l. The equation for the worst-case can be written as follows: R t (min) x (V cc (min)- V TH (max)) R l (max)= 2 x V TH (max) For the worst case conditions, we assume that V CC (min) = 4.75V, that R t (min) = 124 x 0.95 = 117.8Ω, and that the threshold margin is 0.05V, therefore V TH (max)=0.25v. Putting these together, we get:, x ( ) R l (max)= =1060.2Ω 2 x 0.25 Therefore, R l (nominal) = ( / 1.05) = Ω To summarize, R l (nominal)= 1.0KΩ when Rt (nominal) = 124Ω, the threshold margin is.05v, and all resistors have 5% tolerances. R l changes with the threshold margin. For a threshold margin of 0.01V, R l = 1.2kΩ; for a margin of 0.1V, R l = 820Ω. Since the actual I A and I B are not equal to 0, V AB may be less than 0.2V. Further tuning of the resistor values may be required. To do this, measure the voltage between the receiver inputs (V AB ) during an idle period using a digital voltmeter or oscilloscope. Revision 1.0 ( ) USER MANUAL SMSC PCM

13 9.4 RJ11 Pin Out 4 Pin Type 6 Pin Type Pin Number Polarity Figure 9.5 Pin Out of an RJ-11 Modular Jack (Front View) As shown in the figure above, only the two middle pins are used regardless of the number of pins available. The pin just to the left of the middle is always positive (L+) and the pin just to the right of the middle is always negative (L-). 9.5 Routing to Modular Jack Connectors L+ L- 4 Modular 3 jack 2 connector Modular jack connector CN4 CN3 Figure 9.6 Routing to Modular Jack Connectors SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 13

14 10 Transceiver Implementation The use of a non-isolated RS485 transceiver (the method used by the PCM-2074) is shown in the figure below.: Vcc (+5V) RS-485 Transceiver LTC1485 1K TXEN TXD DE DI Drv A B L+ L- RXIN R Rcv 1K RE GND GND Figure 10.1 Non-Isolated RS485 Transceiver 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-purpose conversion adaptor between the PCI slot and the PCM-2074 PCMCIA connector, such as the P111 from Elan Digital Systems (website: Note that there is no guarantee of operation or technical support provided by SMSC for this application. Revision 1.0 ( ) USER MANUAL SMSC PCM

15 12 Care and Usage Information 12.1 Precautions for Handling and Storage 1. 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 or vapor 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 excessive heat during use may damage it. Exposing the board to direct sunlight may cause damage or warpage. 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. The PCM-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 cause short circuits and fire PC Installation Procedure 1. 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 into a 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 De-Installation Procedure 1. 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 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 them to avoid electric contact which may cause a defect in the board, system or peripherals, electric shock, or fire. SMSC PCM-2074 USER MANUAL Revision 1.0 ( ) 15

16 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 for construction 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 licenses under 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 most recently 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. SMSC products 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 injury or 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 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 ARISING FROM 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 THE POSSIBILITY OF SUCH DAMAGES. Revision 1.0 ( ) 16 SMSC SMSC PCM-2074 USER MANUAL