at75c220 ATMEL Corporation, at75c220 Datasheet - Page 47

• Manufacturer Part Number: at75c220
• Description: Smart Internet Appliance Processor Siap
• Manufacturer: ATMEL Corporation

MAC PHY Maintenance Register
Register Name: ETH_MAN
Access Type: Read/write
Reset Value: 0x0
Writing to this register starts the shift register that controls the serial connection to the PHY. On each shift cycle the MDIO
pin becomes equal to the MSB of the shift register and LSB of the shift register becomes equal to the value of the MDIO
pin. When the shifting is complete an interrupt is generated and the IDLE field is set in the Network Status register.
When read will give current shifted value.
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DATA
CODE
REGA
PHYA
RW
HIGH
LOW
For a write operation this is written with the data to be written to the PHY. After a read operation this contains the data
read from the PHY.
Must be written to 10. Will read as written.
Register address. Specifies the register in the PHY to access.
PHY address. Normally will be 0.
Read/write Operation. 10 is read. 01 is write. Any other value is an invalid PHY management frame.
Must be written with 1 to make a valid PHY management frame.
Must be written with 0 to make a valid PHY management frame.
PHYA
LOW
31
23
15
7
HIGH
30
22
14
6
29
21
13
5
RW
REGA
28
20
12
4
DATA
DATA
27
19
11
3
26
18
10
2
PHYA
25
17
9
1
CODE
24
16
8
0
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