Datasheet

557
SAM7X Series [DATASHEET]
6120K–ATARM–11-Feb-14
37.5.7 Receive Status Register
Register Name: EMAC_RSR
Access Type: Read-write
This register, when read, provides details of the status of a receive. Once read, individual bits may be cleared by writing 1 to them.
It is not possible to set a bit to 1 by writing to the register.
• BNA: Buffer Not Available
An attempt was made to get a new buffer and the pointer indicated that it was owned by the processor. The DMA rereads the
pointer each time a new frame starts until a valid pointer is found. This bit is set at each attempt that fails even if it has not had a
successful pointer read since it has been cleared.
Cleared by writing a one to this bit.
• REC: Frame Received
One or more frames have been received and placed in memory. Cleared by writing a one to this bit.
• OVR: Receive Overrun
The DMA block was unable to store the receive frame to memory, either because the bus was not granted in time or because a
not OK hresp(bus error) was returned. The buffer is recovered if this happens.
Cleared by writing a one to this bit.
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
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76543210
–––––OVRRECBNA