GR740-UM-DS, Nov 2017, Version 1.7
216
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GR740
Table 240.
0x10 - GRETH_GBIT MDIO control/status register.
31
16 15
11 10
6
5
4
3
2
1
0
DATA
PHYADDR
REGADDR
NV BU LF RD WR
0x0000
*
0b00000
?
0
1
0
0
rw
rw
rw
?
r
r
rw rw
31: 16
Data (DATA) - Contains data read during a read operation and data that is transmitted is taken from
this field. Reset value: 0x0000.
15: 11
PHY address (PHYADDR) - This field contains the address of the PHY that should be accessed
during a write or read operation. Reset value:
GRETH GBIT 0: “00001”.
GRETH GBIT 1: “00010”
10: 6
Register address (REGADDR) - This field contains the address of the register that should be
accessed during a write or read operation. Reset value: “00000”.
5
RESERVED
4
Not valid (NV) - When an operation is finished (BUSY = 0) this bit indicates whether valid data has
been received that is, the data field contains correct data.
3
Busy (BU) - When an operation is performed this bit is set to one. As soon as the operation is fin-
ished and the management link is idle this bit is cleared.
2
Linkfail (LF) - When an operation completes (BUSY = 0) this bit is set if a functional management
link was not detected.
1
Read (RD) - Start a read operation on the management interface. Data is stored in the data field.
0
Write (WR) - Start a write operation on the management interface. Data is taken from the Data field.
Table 241.
0x14 - GRETH_GBIT transmitter descriptor table base address register.
31
10
9
3
2
0
BASEADDR
DESCPNT
RES
NR
0b0000000
rw
rw
31: 10
Transmitter descriptor table base address (BASEADDR) - Base address to the transmitter descriptor
table.Not Reset.
9: 3
Descriptor pointer (DESCPNT) - Pointer to individual descriptors. Automatically incremented by
the Ethernet MAC.
2: 0
RESERVED
Table 242.
0x18 - GRETH_GBIT receiver descriptor table base address register.
31
10
9
3
2
0
BASEADDR
DESCPNT
RES
NR
0b0000000
rw
rw
31: 10
Receiver descriptor table base address (BASEADDR) - Base address to the receiver descriptor
table.Not Reset.
9: 3
Descriptor pointer (DESCPNT) - Pointer to individual descriptors. Automatically incremented by
the Ethernet MAC.
2: 0
RESERVED