Specifications

Micrel, Inc.
KSZ8895MQ/RQ/FMQ
Pin for Strap-In Options
The KSZ8895MQ/RQ/FMQ can function as a managed switch or an unmanaged switch. If no EEPROM or micro-
controller exists, then the KSZ8895MQ/RQ/FMQ will operate from its default setting. The strap-in option pins can be
configured by external pull-up/down resistors and take effect after power down reset or warm reset. The functions are
described in the following table.
Pin # Pin Name PU/PD
(1)
Description
(1)
1 MDI-XDIS IPD
Disable auto MDI/MDI-X.
Strap option:
PD = (default) = normal operation.
PU = disable auto MDI/MDI-X on all ports.
62 PMRXD3 IPD/O
PHY[5] MII receive bit 3.
Strap option:
PD (default) = enable flow control;
PU = disable flow control.
63 PMRXD2 IPD/O
PHY[5] MII receive bit 2.
Strap option:
PD (default) = disable back pressure;
PU = enable back pressure.
64 PMRXD1 IPD/O
PHY[5] MII receive bit 1.
Strap option:
PD (default) = drop excessive collision packets;
PU = does not drop excessive collision packets.
65 PMRXD0 IPD/O
PHY[5] MII receive bit 0.
Strap option:
PD (default) = disable aggressive back-off algorithm in half-duplex mode;
PU = enable for performance enhancement.
66 PMRXER IPD/O
PHY[5] MII receive error.
Strap option:
PD (default) = 1522/1518 bytes;
PU = packet size up to 1536 bytes.
67 PCRS IPD/O
PHY[5] MII carrier sense
Strap option for Port 4 only.
PD (default) = force half-duplex if auto-negotiation is disabled or fails.
PU = force full-duplex if auto-negotiation is disabled or fails. Refer to register 76.
68 PCOL IPD/O
PHY[5] MII collision detect
Strap option for Port 4 only.
PD (default) = no force flow control.
PU = force flow control. Refer to register 66.
80 SMRXD3 IPD/O
Switch MII receive bit 3.
Strap option:
PD (default) = disable switch SW5-MII full-duplex flow control;
PU = enable switch SW5-MII full-duplex flow control.
81 SMRXD2 IPD/O
Switch MII receive bit 2.
Strap option:
PD (default) = switch SW5-MII in full-duplex mode;
PU = switch SW5-MII in half-duplex mode.
82 SMRXD1 IPD/O
Switch MII receive bit 1.
Strap option:
PD (default) = switch SW5-MII in 100Mbps mode.
PU = switch MII in 10Mbps mode.
March 12, 2014
23
Revision 1.7