Datasheet KSZ8862-16M, KSZ8862-32M (Microchip) - 39

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KSZ8862-16M/-32M
The format for ConfigParam is shown in Table 3-13.
TABLE 3-13: CONFIGPARAM WORD IN EEPROM FORMAT Bit Bit Name Description
15 - 2 Reserved Reserved Internal clock rate selection 0: 125 MHz 1 Clock Rate 1: 25 MHz Note: At power up, this chip operates on 125 MHz clock. The internal fre- quency can be dropped to 25 MHz via the external EEPROM. Async 8-bit or 16-bit bus select 1= bus is configured for 16-bit width 0 ASYN 8-bit 0= bus is configured for 8-bit width (32-bit width, KSZ8862-32, don’t care this bit setting)
3.9 Loopback Support
The KSZ8862M provides loopback support for remote diagnostic of failure. In loopback mode, the speed at both PHY ports will be set to 100BASE-TX full-duplex mode. Two types of loopback are supported: Far-end Loopback and Near- end (Remote) Loopback. 3.9.1 NEAR-END (REMOTE) LOOPBACK Near-end (Remote) loopback is conducted at PHY port 1 of the KSZ8862M. The loopback path starts at the PHY port’s receive inputs (RXPx/RXMx), wraps around at the same PHY port’s PMD/PMA, and ends at the PHY port’s transmit outputs (TXPx/TXMx). Bit [1] of registers P1PHYCTRL and P2PHYCTRL is used to enable near-end loopback for ports 1 and 2, respectively. Alternatively, Bit [9] of registers P1SCSLMD and P2SCSLMD can also be used to enable near-end loopback. The both ports 1 and 2 near-end loopback paths are illustrated Figure 3-9. 3.9.2 Far-End Loopback Far-end loopback is conducted between the KSZ8862M’s two PHY ports. The loopback path starts at the “Originating.” PHY port’s receive inputs (RXP/RXM), wraps around at the “loopback” PHY port’s PMD/PMA, and ends at the “Origi- nating” PHY port’s transmit outputs (TXP/TXM). Bit [8] of registers P1CR4 and P2CR4 is used to enable far-end loopback for ports 1 and 2, respectively. Alternatively, Bit [14] of registers P1MBCR and P2MBCR can also be used to enable far-end loopback. The port 2 far-end loopback path is illustrated in Figure 3-10.  2020 Microchip Technology Inc. DS00003324A-page 39 Document Outline 1.0 Introduction 1.1 General Description 2.0 Pin Description and Configuration 3.0 Functional Description 3.1 Functional Overview: Physical Layer Transceiver 3.2 Functional Overview: MAC and Switch 3.3 Bus Interface Unit (BIU) 3.4 Queue Management Unit (QMU) 3.5 Advanced Switch Functions 3.6 IEEE 802.1Q VLAN Support 3.7 QoS Priority Support 3.8 Rate-Limiting Support 3.9 Loopback Support 4.0 Register Descriptions 4.1 CPU Interface I/O Registers 4.2 Register Map: MAC and PHY 4.3 Type-of-Service (TOS) Priority Control Registers 4.4 Management Information Base (MIB) Counters 4.5 Static MAC Address Table 4.6 Dynamic MAC Address Table 4.7 VLAN Table 5.0 Operational Characteristics 5.1 Absolute Maximum Ratings* 5.2 Operating Ratings** 6.0 Electrical Characteristics 7.0 Timing Specifications 7.1 Asynchronous Timing without using Address Strobe (ADSN = 0) 7.2 Asynchronous Timing using Address Strobe (ADSN) 7.3 Asynchronous Timing using DATACSN 7.4 Address Latching Timing for All Modes 7.5 Synchronous Timing in Burst Write (VLBUSN = 1) 7.6 Synchronous Timing in Burst Read (VLBUSN = 1) 7.7 Synchronous Write Timing (VLBUSN = 0) 7.8 Synchronous Read Timing (VLBUSN = 0) 7.9 Auto-Negotiation Timing 7.10 Reset Timing 7.11 EEPROM Timing 8.0 Selection of Isolation Transformers 9.0 Package Outline 9.1 Package Marking Information Appendix A: Data Sheet Revision History The Microchip Website Customer Change Notification Service Customer Support Product Identification System Worldwide Sales and Service