High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
14.3.6
Host MAC MII Access Register (HMAC_MII_ACC)
Offset:
6h
Size:
32 bits
This read/write register is used in conjunction with the Host MAC MII Data Register (HMAC_MII_DATA)
to access the internal PHY registers. Refer to Section 14.4, "Ethernet PHY Control and Status
Registers" for a list of accessible PHY registers and PHY address information.
BITS
DESCRIPTION
TYPE
DEFAULT
31:16
15:11
RESERVED
RO
-
PHY Address (PHY_ADDR)
R/W
00000b
This field must be loaded with the PHY address that the MII access is
intended for. A list default PHY addresses can be seen in Table 7.1. Refer
to Section 7.1.1, "PHY Addressing," on page 82 for additional information on
PHY addressing.
10:6
MII Register Index (MIIRINDA)
These bits select the desired MII register in the PHY.
R/W
00000b
5:2
1
RESERVED
RO
-
MII Write (MIIWnR)
R/W
0b
Setting this bit tells the PHY that this will be a write operation using the Host
MAC MII Data Register (HMAC_MII_DATA). If this bit is cleared, a read
operation will occur, packing the data in the Host MAC MII Data Register
(HMAC_MII_DATA).
0
MII Busy (MIIBZY)
R/W
SC
0b
This bit must be polled to determine when the MII register access is
complete. This bit must read a logical 0 before writing to this register or the
Host MAC MII Data Register (HMAC_MII_DATA).
The LAN driver software must set this bit in order for the
LAN9312 to read or write any of the MII PHY registers.
During a MII register access, this bit will be set, signifying a read or write
access is in progress. The MII data register must be kept valid until the Host
MAC clears this bit during a PHY write operation. The MII data register is
invalid until the Host MAC has cleared this bit during a PHY read operation.
Revision 1.2 (04-08-08)
278
SMSC LAN9312
DATASHEET
SMSC [ SMSC CORPORATION ]
