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8.14.4
Management Data Input/Output (MDIO)
TMS320TCI6482
Communications Infrastructure Digital Signal Processor
SPRS246F–APRIL 2005–REVISED MAY 2007
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 8-58
.
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 8-70
above 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
TMS320TCI648x DSP EMAC/MDIO Module
Reference Guide
(literature number
SPRUE12
).
8.14.4.1
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.
8.14.4.2
MDIO Peripheral Register Description(s)
Table 8-89. MDIO Registers
HEX ADDRESS RANGE
02C8 1800
02C8 1804
02C8 1808
02C8 180C
02C8 1810
02C8 1814
02C8 1818 - 02C8 181C
02C8 1820
02C8 1824
02C8 1828
02C8 182C
02C8 1830 - 02C8 187C
02C8 1880
02C8 1884
02C8 1888
02C8 188C
02C8 1890 - 02C8 1FFF
ACRONYM
VERSION
CONTROL
ALIVE
LINK
LINKINTRAW
LINKINTMASKED
-
USERINTRAW
USERINTMASKED
USERINTMASKSET
USERINTMASKCLEAR
-
USERACCESS0
USERPHYSEL0
USERACCESS1
USERPHYSEL1
-
REGISTER NAME
MDIO Version Register
MDIO Control Register
MDIO PHY Alive Status Register
MDIO PHY Link Status Register
MDIO Link Status Change Interrupt (Unmasked) Register
MDIO Link Status Change Interrupt (Masked) Register
Reserved
MDIO User Command Complete Interrupt (Unmasked) Register
MDIO User Command Complete Interrupt (Masked) Register
MDIO User Command Complete Interrupt Mask Set Register
MDIO User Command Complete Interrupt Mask Clear Register
Reserved
MDIO User Access Register 0
MDIO User PHY Select Register 0
MDIO User Access Register 1
MDIO User PHY Select Register 1
Reserved
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