Datasheet

Section 21 Ethernet Controller Direct Memory Access Controller (E-DMAC)
Rev. 2.00 Aug. 20, 2008 Page 811 of 1198
REJ09B0403-0200
21.2.14 Receiving-Descriptor Fetch Address Register (RDFAR)
RDFAR stores the descriptor start address that is required when the E-DMAC fetches descriptor
information from the receiving descriptor. Which receiving descriptor information is used for
processing by the E-DMAC can be recognized by monitoring addresses displayed in this register.
The address from which the E-DMAC is actually fetching a descriptor may be different from the
value read from this register.
Bit Bit Name
Initial
value
R/W Description
31 to 0 RDFA31 to
RDFA0
All 0 R Receiving-Descriptor Fetch Address
These bits can only be read. Writing is prohibited.
21.2.15 Transmission-Buffer Read Address Register (TBRAR)
TBRAR stores the address of the transmission buffer when the E-DMAC reads data from the
transmission buffer. Which addresses in the transmission buffer are processed by the E-DMAC
can be recognized by monitoring addresses displayed in this register. The address from which the
E-DMAC is actually reading in the buffer may be different from the value read from this register.
Bit Bit Name
Initial
value
R/W Description
31 to 0 TBRA31 to
TBRA0
All 0 R Transmission-Buffer Read Address
These bits can only be read. Writing is prohibited.
21.2.16 Transmission-Descriptor Fetch Address Register (TDFAR)
TDFAR stores the descriptor start address that is required when the E-DMAC fetches descriptor
information from the transmission descriptor. Which transmission descriptor information is used
for processing by the E-DMAC can be recognized by monitoring addresses displayed in this
register. The address from which the E-DMAC is actually fetching a descriptor may be different
from the value read from this register.
Bit Bit Name
Initial
value
R/W Description
31 to 0 TDFA31 to
TDFA0
All 0 R Transmission-Descriptor Fetch Address
These bits can only be read. Writing is prohibited.