User Manual

AT75C220

MAC Interrupt Status Register

Access Type: Read/write

Reset Value: 0x0

• DONE

Management done. The PHY maintenance register has completed its operation. Cleared on read.

• RCOM

Receive complete. A frame has been stored in memory. Cleared on read.

• RBNA

Receive buffer not available. Cleared on read.

• TOVR

Transmit buffer overrun. Software wrote to the address register or length register when bit 4 of the transmit status reg-

ister was not set. Cleared on read.

• TUND

Transmit error. Ethernet transmit buffer underrun. The transmit DMA did not complete fetch frame data in time for it to

be transmitted. Cleared on read.

• TRLE

Transmit error. Retry limit exceeded. Cleared on read.

• TBRE

Transmit buffer register empty. Software may write a new buffer address and length to the transmit DMA controller.

Cleared by having one frame ready to transmit and another in the process of being transmitted. Cleared on read.

• TCOM

Transmit complete. Set when a frame has been transmitted. Cleared on read.

• LINK

Set when LINK pin changes value. Optional.

• TIDLE

Transmit idle. Set when all frames have been transmitted. Cleared on read.

• ROVR

RX overrun. Set when the RX overrun status bit is set. Cleared on read.

• HRESP

HRESP not OK. Set when the DMA block sees HRESP not OK. Cleared on read.

31 30 29 28 27 26 25 24

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23 22 21 20 19 18 17 16

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15 14 13 12 11 10 9 8

––––HRESP ROVR LINK TIDLE

76543210

TCOM TBRE RTRY TUND TOVR RBNA RCOM DONE