 2009-2019 Microchip Technology Inc.

DS00003050A-page 3

KSZ9021RL/RN

Table of Contents

1.0 Introduction ..................................................................................................................................................................................... 4

2.0 Pin Description and Configuration .................................................................................................................................................. 5

3.0 Functional Overview ..................................................................................................................................................................... 23

4.0 Register Description ...................................................................................................................................................................... 37

5.0 Operational Characteristics ........................................................................................................................................................... 50

6.0 Timing Diagrams ........................................................................................................................................................................... 53

7.0 Package Information ..................................................................................................................................................................... 60

Appendix A: Data Sheet Revision History ........................................................................................................................................... 63

The Microchip Web Site ...................................................................................................................................................................... 64

Customer Change Notification Service ............................................................................................................................................... 64

Customer Support ............................................................................................................................................................................... 64

Product Identification System ............................................................................................................................................................. 65