KSZ8061MNX Datasheet, PDF (23/64 Pages) Microchip Technology – 10BASE-T/100 BASE-TX Physical Layer Transceiver

1. MII MAC transmits frames to KSZ8061MN.
2. Frames are wrapped around inside KSZ8061MN.
3. KSZ8061MN transmits frames back to MII MAC.
FIGURE 3-7:
LOCAL (DIGITAL) LOOPBACK
KSZ8061MN
KSZ8061MNX/MNG
AFE
PCS
MII
(ANALOG)
(DIGITAL)
MII
MAC
The following programming steps and register settings are used for Local Loopback mode.
For 10/100 Mbps loopback,
1. Set Register 0h,
•Bit [14] = 1 // Enable Local Loopback mode
•Bit [13] = 0/1 // Select 10 Mbps/100 Mbps speed
•Bit [12] = 0 // Disable Auto-Negotiation
•Bit [8] = 1 // Select full-duplex mode
2. Set Register 1Ch,
•Bit [5] = 1
3.11.2 REMOTE (ANALOG) LOOPBACK
This loopback mode checks the line (differential pairs, transformer, RJ-45 connector, Ethernet cable) transmit and
receive data paths between KSZ8061MN and its link partner, and is supported for 100BASE-TX full-duplex mode only.
The loopback data path is shown in the following Figure 3-8.
1. Fast Ethernet (100BASE-TX) PHY Link Partner transmits frames to KSZ8061MN.
2. Frames are wrapped around inside KSZ8061MN.
3. KSZ8061MN transmits frames back to Fast Ethernet (100BASE-TX) PHY Link Partner.
FIGURE 3-8:
REMOTE (ANALOG) LOOPBACK
KSZ8061MN
RJ-45
AFE
PCS
MII
(ANALOG)
(DIGITAL)
CAT-5
(UTP)
RJ-45
100BASE-TX
LINK PARTNER
 2016 Microchip Technology Inc.
DS00002038A-page 23