Texas Instruments SM320C6455-EP manual Management Data Input/Output Mdio

SM320C6455-EP

FIXED-POINT DIGITAL SIGNAL PROCESSOR

www.ti.com

SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008

7.14.4Management Data Input/Output (MDIO)

The Management Data Input/Output (MDIO) module implements the 802.3 serial management interface to interrogate and controls up to 32 Ethernet PHY(s) connected to the device, using a shared two-wire bus. Application software uses the MDIO module to configure the auto-negotiation parameters of each PHY attached to the EMAC, retrieve the negotiation results, and configure required parameters in the EMAC module for correct operation. The module is designed to allow almost transparent operation of the MDIO interface, with very little maintenance from the core processor.

The EMAC control module is the main interface between the device core processor, the MDIO module, and the EMAC module. The relationship between these three components is shown in Figure 7-58.

The MDIO uses the same pins for the MII, GMII, and RMII modes. Standalone pins are included for the RGMII mode due to specific voltage requirements. Only one mode can be used at a time. The mode used is selected at device reset based on the MACSEL[1:0] configuration pins (for more detailed information, see Section 3, Device Configuration). Table 7-70above shows which multiplexed pin are used in the MII, GMII, and RMII modes on the MDIO.

For more detailed information on the EMAC/MDIO, see the TMS320C645x DSP EMAC/MDIO Module Reference Guide (literature number SPRU975).

7.14.4.1 MDIO Device-Specific Information

Clocking Information

The MDIO clock is based on a divide-down of the SYSCLK3 (from the PLL1 controller) and is specified to run up to 2.5 MHz, although typical operation is 1.0 MHz. Since the peripheral clock frequency is variable, the application software or driver controls the divide-down amount.

7.14.4.2 MDIO Peripheral Register Description(s)

Table 7-89. MDIO Registers

HEX ADDRESS RANGE	ACRONYM	REGISTER NAME
02C8 1800	VERSION	MDIO Version Register
02C8 1804	CONTROL	MDIO Control Register
02C8 1808	ALIVE	MDIO PHY Alive Status Register
02C8 180C	LINK	MDIO PHY Link Status Register
02C8 1810	LINKINTRAW	MDIO Link Status Change Interrupt (Unmasked) Register
02C8 1814	LINKINTMASKED	MDIO Link Status Change Interrupt (Masked) Register
02C8 1818 - 02C8 181C	-	Reserved
02C8 1820	USERINTRAW	MDIO User Command Complete Interrupt (Unmasked) Register
02C8 1824	USERINTMASKED	MDIO User Command Complete Interrupt (Masked) Register
02C8 1828	USERINTMASKSET	MDIO User Command Complete Interrupt Mask Set Register
02C8 182C	USERINTMASKCLEAR	MDIO User Command Complete Interrupt Mask Clear Register
02C8 1830 - 02C8 187C	-	Reserved
02C8 1880	USERACCESS0	MDIO User Access Register 0
02C8 1884	USERPHYSEL0	MDIO User PHY Select Register 0
02C8 1888	USERACCESS1	MDIO User Access Register 1
02C8 188C	USERPHYSEL1	MDIO User PHY Select Register 1
02C8 1890 - 02C8 1FFF	-	Reserved

216 C64x+ Peripheral Information and Electrical Specifications Submit Documentation Feedback