Atmel Evaluation Kit for AT32uC3A0512, 32-Bit AVR Microcontroller Atmel ATEVK1105 ATEVK1105 Data Sheet
Product codes
ATEVK1105
463
AT32UC3A
29.7.6
Transmit Buffer Queue Pointer Register
Register Name:
TBQP
Access Type:
Read/Write
This register points to the entry in the transmit buffer queue (descriptor list) currently being used. It is written with the start
location of the transmit 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. This register can only be written when bit 3 in the
transmit status register is low.
As transmit buffer reads consist of bursts of two words, it is recommended that bit 2 is always written with zero to prevent a
As transmit buffer reads consist of bursts of two words, 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:
Transmit buffer queue pointer address
Written with the address of the start of the transmit queue, reads as a pointer to the first buffer of the frame being transmit-
ted or about to be transmitted.
31
30
29
28
27
26
25
24
ADDR
23
22
21
20
19
18
17
16
ADDR
15
14
13
12
11
10
9
8
ADDR
7
6
5
4
3
2
1
0
ADDR
–
–
32058K
AVR32-01/12