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| PMC-Sierra, Inc. PM5355 S/UNI-622 ERRATA PMC-970820 ISSUE 1 SUNI/-622 REFERNECE DESIGN WITH MULTIMODE OPTICS ERRATA PM5355 S/UNI-622TM ATM Reference Design with Multimode Optics Errata Issue 1: August 14, 1997 PMC-Sierra, Inc. 105 - 8555 Baxter Place Burnaby, BC Canada V5A 4V7 (604) 415-6000 PMC-Sierra, Inc. PM5355 S/UNI-622 ERRATA PMC-970820 ISSUE 1 SUNI/-622 REFERNECE DESIGN WITH MULTIMODE OPTICS ERRATA CONTENTS THE SUN/I-622 REFERNCE DESIGN ERRATA .........................................1 1.0 TRANSMIT AND RECEIVE CLOCK TERMINATIONS ................................1 2.0 INTERFACE TIMING BETWEEN THE VSC8110 AND THE S/UNI-622...........2 i PMC-Sierra, Inc. PM5355 S/UNI-622 ERRATA PMC-970820 ISSUE 1 SUNI/-622 REFERNECE DESIGN WITH MULTIMODE OPTICS ERRATA THE S/UNI-622 REFERENCE DESIGN ERRATA This document is the errata notice for Issue 3 of the S/UNI-622 reference design with multimode optics. It addresses transmit and receive clock terminations and interfacing timing issues in the S/UNI-622 reference design. 1.0 TRANSMIT AND RECEIVE CLOCK TERMINATIONS The Vitesse VSC8110 clock output loading presents a problem. The VSC8110 spec shows Vol = 0.5 V at 8 mA, and Voh = 2.4V at 2.4 mA. The original design has a 220 pullup resistor and a 330 pulldown resistor. Voh does not present a problem, but Vol would have to sink (3 V-0.5 V)/132 = 18.9 mA. This is 10.9 mA higher than what the VSC8110 can sink. To address the problem, the resistors should be changed to 470 for the pullup one and 300 for the pulldown one. Figure 1 shows the new pullup and pulldown resistors for both S/UNI-622's PICLK and VSC8110`s TXLSCKIN terminations. Figure 1. New values for the pullup and pulldown resistors +5V 470 RXLSCKOUT 300 TXLSCKOUT PICLK TCLK Vitesse VSC8110 TXLSCKIN +5V 470 PM-5355 S/UNI-622 300 1 PMC-Sierra, Inc. PM5355 S/UNI-622 ERRATA PMC-970820 ISSUE 1 SUNI/-622 REFERNECE DESIGN WITH MULTIMODE OPTICS ERRATA 2.0 INTERFACE TIMING BETWEEN THE VSC8110 AND THE S/UNI-622 In the implementation section of sheet 2, S/UNI-622 Interconnect, on bottom of page 5, concerns were raised regarding to a 0.2 ns timing margin. This is shown as below. The entire section on the 0.2ns margin and the related timing diagram can be omitted since this timing requirement does not apply to the Vitesse VSC8110 and replaced with the following: This identical timing exists with the FPIN input as well as the PIN[7:0]. Since there is only a 0.2ns timing margin on the setup time (data valid to the rising edge of clock) on the FPIN and PIN[7:0] inputs, precautions must be taken to avoid skew between these inputs. In fact, a slight delay (in the order of 1-5ns) in the data path would be advantageous and a slight delay (greater than 0.2ns) in the clock path would be intolerable. Hold time is not a concern on this interface since only 3ns are required and there are 11.9ns available. The Vitesse VSC8110 data sheet specifies that data is valid on RXOUT[7:0] at 4.9 ns before and after the rising edge of RXLSCKOUT. For the S/UNI-622, both the PIN[7:0] and FPIN has a setup time requirement of 3.5 ns and hold time of 1 ns. The Vitesse timing specification meets S/UNI-622's timing requirements with 1.4 ns margin for setup and 3.9 ns margin for hold time. Figure 2 shows the new timing between the VSC8110 and the S/UNI-622. Figure 2 VSC8110 and S/UNI-622 Receive Interface Timing 0 ns 3 .1 2 n s 6 .2 5 n s 9 .3 8 n s 1 2 .5 0 n s 1 5 .6 2 n s 1 8 .7 5 n s P IC L K P IN [7 :0 ] 4 .9 n s 4 .9 n s 4 .9 n s 1 .4 n s 3 .5 n s m in re q 1 ns m in 3 .9 n s 1 2 .8 6 n s 2 PMC-Sierra, Inc. PM5355 S/UNI-622 ERRATA PMC-970820 ISSUE 1 SUNI/-622 REFERNECE DESIGN WITH MULTIMODE OPTICS ERRATA CONTACTING PMC-SIERRA PMC-Sierra, Inc. 105-8555 Baxter Place Burnaby, BC Canada V5A 4V7 Tel: Fax: (604) 415-6000 (604) 415-6200 Document Information: document@pmc-sierra.com Corporate Information: info@pmc-sierra.com Applications Information: apps@pmc-sierra.com Web Site: http://www.pmc-sierra.com ____________________________________________________________________________________________ _ Seller will have no obligation or liability in respect of defects or damage caused by unauthorized use, mis-use, accident, external cause, installation error, or normal wear and tear. There are no warranties, representations or guarantees of any kind, either express or implied by law or custom, regarding the product or its performance, including those regarding quality, merchantability, fitness for purpose, condition, design, title, infringement of thirdparty rights, or conformance with sample. Seller shall not be responsible for any loss or damage of whatever nature resulting from the use of, or reliance upon, the information contained in this document. In no event will Seller be liable to Buyer or to any other party for loss of profits, loss of savings, or punitive, exemplary, incidental, consequential or special damages, even if Seller has knowledge of the possibility of such potential loss or damage and even if caused by Seller's negligence. (c) 1997 PMC-Sierra, Inc. PMC-970820 (R1) ref PMC-950860 (R3) Issue date: August 1997. PMC-Sierra, Inc. 105 - 8555 Baxter Place Burnaby, BC Canada V5A 4V7 (604) 415-6000 |
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