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Architecture

The receive host error conditions are:

• Ownership bit not set in input buffer

• Zero buffer pointer

The application software must acknowledge the EMAC control module after receiving host error interrupts

by writing the appropriate CnMISC key to the EMAC End-Of-Interrupt Vector (MACEOIVECTOR). See

Section 5.12 for the acknowledge key values.

2.16.1.5 Receive Threshold Interrupts

Each of the eight receive channels have a corresponding receive threshold interrupt (RXnTHRESHPEND).

The receive threshold interrupts are level interrupts that remain asserted until the triggering condition is

cleared by the host. Each of the eight threshold interrupts may be individually enabled by setting to 1 the

appropriate bit in the RXINTMASKSET register. Each of the eight channel interrupts may be individually

disabled by clearing to zero the appropriate bit by writing a 1 in the receive interrupt mask clear register

(RXINTMASKCLEAR). The raw and masked interrupt receive interrupt status may be read by reading the

receive interrupt status (unmasked) register (RXINTSTATRAW) and the receive interrupt status (masked)

An RXnTHRESHPEND interrupt bit is asserted when enabled and when the channel’s associated free

buffer count (RXnFREEBUFFER) is less than or equal to the channel’s associated flow control threshold

threshold logic as does flow control, but the interrupts are independently enabled from flow control. The

threshold interrupts are intended to give the host an indication that resources are running low for a

particular channel(s).

The applications software must acknowledge the EMAC control module after receiving threshold interrupts

by writing the appropriate CnRXTHRESH key to the EMAC End-Of-Interrupt Vector (MACEOIVECTOR).

See Section 5.12 for the acknowledge key values.

2.16.2 MDIO Module Interrupt Events and Requests

The MDIO module generates two interrupt events:

• LINKINT0: Serial interface link change interrupt. Indicates a change in the state of the PHY link

selected by the USERPHYSEL0 register

• USERINT0: Serial interface user command event complete interrupt selected by the USERACCESS0

2.16.2.1 Link Change Interrupt

The MDIO module asserts a link change interrupt (LINKINT0) if there is a change in the link state of the

PHY corresponding to the address in the PHYADRMON bit in the MDIO register USERPHYSEL0, and if

the LINKINTENB bit is also set in USERPHYSEL0. This interrupt event is also captured in the

LINKINTRAW bit in the MDIO link status change interrupt register (LINKINTRAW). LINKINTRAW bits 0

and 1 correspond to USERPHYSEL0 and USERPHYSEL1, respectively.

When the interrupt is enabled and generated, the corresponding LINKINTMASKED bit is also set in the

MDIO link status change interrupt register (LINKINTMASKED). The interrupt is cleared by writing back the

same bit to LINKINTMASKED (write to clear).

The application software must acknowledge the EMAC control module after receiving MDIO interrupts by

writing the appropriate CnMISC key to the EMAC End-Of-Interrupt Vector (MACEOIVECTOR). See

Section 5.12 for the acknowledge key values.

SPRUFL5B–April 2011 EMAC/MDIO Module

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