DS80C400 Maxim, DS80C400 Datasheet - Page 56

• Manufacturer Part Number: DS80C400
• Description: The DS80C400 network microcontroller offers the highest integration available in an 8051 device
• Manufacturer: Maxim

CSR Register:
Register Address:
Bit Names:
Reset State:
PHYA[4:0], PHY Address [4:0]. This 5-bit address specifies the PHY address for 2-wire MII serial-management
bus communication.
PHYR[4:0], PHY Register Select [4:0]. This 5-bit field specifies the PHY register to be accessed in 2-wire MII
serial-management bus communication.
W/R, Write/Read. This bit is used to indicate whether a write or read operation is to be requested of the addressed
PHY/PHY register.
0 = read
1 = write
BUSY, Busy. This status bit indicates when PHY communication is currently taking place on the MII serial-
management bus. The application must wait until BUSY = 0 before modifying the MII address and MII data
registers prior to each read/write operation.
0 = MII serial-management bus idle
1 = MII serial-management bus busy (write/read in progress)
CSR Register:
Register Address:
Bit Names:
Reset State:
PHYD[15:0], PHY Data [15:0]. These 16 bits contain the data read from the PHY register following a read
operation, or the data to be written to the PHY register prior to a write operation.
31
23
15
7
31
23
15
7
31
23
15
7
31
23
15
7
—
—
—
—
0
0
0
0
0
0
0
0
PHYR [1:0]
MII Address
14h
—
—
MII Data
18h
—
—
0
0
0
0
0
0
0
0
PHYA [4:0]
—
—
—
—
—
0
0
0
0
0
0
0
0
—
—
—
—
—
0
0
0
0
0
0
0
0
PHYD [15:8]
PHYD [7:0]
56 of 97
—
—
—
—
—
0
0
0
0
0
0
0
0
—
—
—
—
—
0
0
0
0
0
0
0
0
PHYR [4:2]
W/ R
—
—
—
—
0
0
0
0
0
0
0
0
BUSY
—
—
—
—
0
0
0
0
0
0
0
0
24
16
8
0
24
16
8
0
24
16
8
0
24
16
8
0