Texas Instruments TMS320DM646x manual PHY Acknowledge Status Register ALIVE

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MDIO Registers

4.3PHY Acknowledge Status Register (ALIVE)

The PHY acknowledge status register (ALIVE) is shown in Figure 29 and described in Table 27.

	Figure 29. PHY Acknowledge Status Register (ALIVE)
31	16
	ALIVE
	R/W1C-0
15	0
	ALIVE

R/W1C-0

LEGEND: R/W = Read/Write; W1C = Write 1 to clear, write of 0 has no effect; -n= value after reset

Table 27. PHY Acknowledge Status Register (ALIVE) Field Descriptions

Bit	Field	Value	Description
31-0	ALIVE	0-FFFF FFFFh	MDIO Alive bits. Each of the 32 bits of this register is set if the most recent access to the PHY with
			address corresponding to the register bit number was acknowledged by the PHY; the bit is reset if
			the PHY fails to acknowledge the access. Both the user and polling accesses to a PHY will cause
			the corresponding alive bit to be updated. The alive bits are only meant to be used to give an
			indication of the presence or not of a PHY with the corresponding address. Writing a 1 to any bit
			will clear it, writing a 0 has no effect.
		0	The PHY fails to acknowledge the access.

1The most recent access to the PHY with an address corresponding to the register bit number was acknowledged by the PHY.

4.4PHY Link Status Register (LINK)

The PHY link status register (LINK) is shown in Figure 30 and described in Table 28.

	Figure 30. PHY Link Status Register (LINK)
31	16
	LINK
	R-0
15	0

LINK

R-0

LEGEND: R = Read only; -n= value after reset

Table 28. PHY Link Status Register (LINK) Field Descriptions

Bit	Field	Value	Description
31-0	LINK	0-FFFF FFFFh	MDIO Link state bits. This register is updated after a read of the generic status register of a PHY.
			The bit is set if the PHY with the corresponding address has link and the PHY acknowledges the
			read transaction. The bit is reset if the PHY indicates it does not have link or fails to acknowledge
			the read transaction. Writes to the register have no effect.
		0	The PHY indicates it does not have a link or fails to acknowledge the read transaction
		1	The PHY with the corresponding address has a link and the PHY acknowledges the read
			transaction.

SPRUEQ6–December 2007	Ethernet Media Access Controller (EMAC)/Management Data Input/Output (MDIO)	73
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