
Micrel, Inc.
KSZ8841-PMQL
October 2007
23
M9999-100407-1.5
Bit
Name
Description
3
PME_CK
PME Clock
When this bit is a “1”, it indicates that the function relies on the presence of the PCI
clock for PME# operation.
When this bit is a “0”, it indicates that no PCI clock is required for the function to
generate PME#. This bit is loaded to bit 3 of PMCR register and bit 19 of CCID
register.
2 - 0
PCI: PME_VER
PCI: Power Management PCI Version. These bits are loaded to bits [2-0] of the
PMCR register and bits [18-16] of the CCID register.
Table 3. KSZ8841-PMQL ConfigParam in EEPROM Format
Loopback Support
The KSZ8841-PMQL provides loopback support for remote diagnostic failure. In loopback mode, the speed at the PHY
port will be set to 100BASE-TX full-duplex mode. The KSZ8841-PMQL only supports Near-end (Remote) Loopback.
Near-end (Remote) loopback is conducted at PHY port 1 of the KSZ8841-PMQL. The loopback path starts at the PHY
ports receive inputs (RXPx/RXMx), wraps around at the same PHY port’s PMD/PMA, and ends at the PHY ports
transmit outputs (TXPx/TXMx).
Bit [1] of register P1PHYCTRL is used to enable near-end loopback for port 1. Alternatively, Bit [9] of register
P1SCSLMD can also be used to enable near-end loopback. The port’s near-end loopback path is illustrated in the
following Figure 4.
PCI Bus I/F Unit
RX/TX DMA
8K RX/TX Buffer
MAC1
PCS1
PMD1/PMA1
RXP1 /
RXM1
TXP1 /
TXM1
PHY Port 1
Near-end (remote)
Loopback
Figure 6. Port 1 Near-End (Remote) Loopback Path