WAKE_UP - “Magic Packet” is received if enabled

RX_OVRN INT - Set when the receiver overruns due to a failed memory allocation. The RX_OVRN bit of the EPHSR will also be set, but if a new packet is received it will be cleared. The RX_OVRN INT bit, however, latches the overrun condition for the purpose of being polled or generating an interrupt, and will only be cleared by writing the acknowledge register with the RX_OVRN INT bit set.

ALLOC INT - Set when an MMU request for TX pages allocation is completed. This bit is the complement of the FAILED bit in the ALLOCATION RESULT register. The ALLOC INT ENABLE bit should only be set following an allocation command, and cleared upon servicing the interrupt.

TX EMPTY INT - Set if the TX FIFO goes empty, can be used to generate a single interrupt at the end of a sequence of packets enqueued for transmission. This bit latches the empty condition, and the bit will stay set until it is specifically cleared by writing the acknowledge register with the TX EMPTY INT bit set. If a real time reading of the FIFO empty is desired, the bit should be first cleared and then read. The TX EMPTY INT ENABLE should only be set after the following steps:

a)a packet is enqueued for transmission

b)the previous empty condition is cleared (acknowledged)

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TX INT - Set when at least one packet transmission was completed. The first packet number to be serviced can be read from the FIFO PORTS register. The TX INT bit is always the logic complement of the TEMPTY bit in the FIFO PORTS register. After servicing a packet number, its TX INT interrupt is removed by writing the Interrupt Acknowledge Register with the TX INT bit set.

RCV INT - Set when a receive interrupt is generated. The first packet number to be serviced can be read from the FIFO PORTS register. The RCV INT bit is always the logic complement of the REMPTY bit in the FIFO PORTS register.

ERCV INT - Early receive interrupt. Set whenever a receive packet is being received, and the number of bytes received into memory exceeds the value programmed as ERCV THRESHOLD (Bank 3,

Offset Ch). ERCV INT stays set until acknowledged by writing the INTERRUPT ACKNOWLEDGE REGISTER with the ERCV INT bit set.

NOTE: If the driver uses AUTO RELEASE mode it should enable TX EMPTY INT as well as TX INT. TX EMPTY INT will be set when the complete sequence of packets is transmitted. TX INT will be set if the sequence stops due to a fatal error on any of the packets in the sequence.

NOTE: For edge triggered systems, the Interrupt Service Routine should clear the Interrupt Mask Register, and only enable the appropriate interrupts after the interrupt source is serviced (acknowledged).

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SMC Networks SMC91C95 manual