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KSZ8864RMN Datasheet, PDF (47/112 Pages) Micrel Semiconductor – Integrated 4-Port 10/100 Managed Switch with Two MACs MII or RMII Interfaces | |||
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Micrel, Inc.
KSZ8864RMN
SMI register Read access is selected when OP Code is set to â10â and bits [2:1] of the PHY address is set to â11â.
The 8-bit register address is the concatenation of {PHY address bits [4:3], PHY address bits [0], REG address bit
[4:0]}. TA is turn-around bits. TA bits [1:0] are âZ0â means the processor MDIO pin is changed to input Hi-Z from
output mode and the followed â0â is the read response from device, as the switch configuration registers are 8-bit
wide, only the lower 8 bits of data bits [15:0] are used
SMI register Write access is selected when OP Code is set to â01â and bits [2:1] of the PHY address is set to â11â.
The 8-bit register address is the concatenation of {PHY address bits [4:3], PHY address bits [0], REG address bit
[4:0]}. TA bits [1:0] are set to â10â, as the switch configuration registers are 8-bit wide, only the lower 8 bits of data bits
[15:0] are used.
To access the KSZ8864RMN registers 0-255 (0x00 â 0xFF), the following applies:
PHYAD [4, 3, 0] and REGAD [4:0] are concatenated to form the 8-bit address; that is, {PHYAD [4,3,0], REGAD[4:0]}
= bits [7:0] of the 8-bit address.
Registers are eight data bits wide. For read operation, data bits [15:8] are read back as 0âs. For write operation, data
bits [15:8] are not defined, and hence can be set to either 0s or 1s.
SMI register access is the same as the MIIM register access, except for the register access requirements presented
in this section.
September 2011
47
M9999-092011-1.4
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