Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet
Product codes
ATSAM4E-XPRO
1231
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
43.7.7 Receive Buffer Queue Base Address Register
Name:
GMAC_RBQB
Address:
0x40034018
Access: Read/Write
This register holds the start address of the receive buffer queue (receive buffers descriptor list). The receive buffer queue
base address must be initialized before receive is enabled through bit 2 of the Network Control Register. Once reception is
enabled, any write to the Receive Buffer Queue Base Address Register is ignored. Reading this register returns the loca-
tion 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 constantly changes as new frames are
received. Software should instead work its way through the buffer descriptor queue checking the “used” bits.
base address must be initialized before receive is enabled through bit 2 of the Network Control Register. Once reception is
enabled, any write to the Receive Buffer Queue Base Address Register is ignored. Reading this register returns the loca-
tion 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 constantly changes as new frames are
received. Software should instead work its way through the buffer descriptor queue checking the “used” bits.
In terms of AMBA AHB operation, the descriptors are read from memory using a single 32-bit AHB access. The descriptors
should be aligned at 32-bit boundaries and the descriptors are written to using two individual non sequential accesses.
should be aligned at 32-bit boundaries and the descriptors are written to using two individual non sequential accesses.
ADDR: Receive Buffer Queue Base Address
Written with the address of the start of the receive queue.
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ADDR
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ADDR
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ADDR
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