at91sam9263 ATMEL Corporation, at91sam9263 Datasheet - Page 797

• Manufacturer Part Number: at91sam9263
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

40.5.6
Register Name:
Access Type:
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
burst crossing a 1K boundary, in violation of section 3.6 of the AMBA 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.
6249D–ATARM–20-Dec-07
31
23
15
7
Transmit Buffer Queue Pointer Register
30
22
14
EMAC_TBQP
Read/Write
6
29
21
13
5
ADDR
28
20
12
4
ADDR
ADDR
ADDR
27
19
11
3
AT91SAM9263 Preliminary
26
18
10
2
25
17
9
1
–
24
16
8
0
–
797