Atmel Evaluation Kit for AT32uC3A0512, 32-Bit AVR Microcontroller Atmel ATEVK1105 ATEVK1105 Data Sheet
Product codes
ATEVK1105
462
AT32UC3A
29.7.5
Receive Buffer Queue Pointer Register
Register Name:
RBQP
Access Type:
Read/Write
This register points to the entry in the receive buffer queue (descriptor list) currently being used. It is written with the start
location of the receive buffer descriptor list. The lower order bits increment as buffers are used up and wrap to their original
values after either 1024 buffers or when the wrap bit of the entry is set.
Reading this register returns the location of the descriptor currently being accessed. This value increments as buffers are
Reading this register returns the location of the descriptor currently being accessed. This value increments as buffers are
used. Software should not use this register for determining where to remove received frames from the queue as it con-
stantly changes as new frames are received. Software should instead work its way through the buffer descriptor queue
checking the used bits.
Receive buffer writes also comprise bursts of two words and, as with transmit buffer reads, it is recommended that bit 2 is
Receive buffer writes also comprise bursts of two words and, as with transmit buffer reads, it is recommended that bit 2 is
always written with zero to prevent a burst crossing a 1K boundary, in violation of the System Bus specification.
• ADDR:
Receive buffer queue pointer address
Written with the address of the start of the receive queue, reads as a pointer to the current buffer being used.
31
30
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24
ADDR
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16
ADDR
15
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9
8
ADDR
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3
2
1
0
ADDR
–
–
32058K
AVR32-01/12