LM3S6952 Datasheet, PDF (439/626 Pages) Texas Instruments – Stellaris LM3S6952 Microcontroller

Stellaris® LM3S6952 Microcontroller
APOL is clear and RVSPOL indicates if the detection circuitry has inverted the input signal. To enter
manual mode, APOL should be set. In manual mode RVSPOL controls the signal polarity.
16.2.3.4
MDI/MDI-X Configuration
The Ethernet Controller supports the MDI/MDI-X configuration as defined in IEEE 802.3-2002
specification. The MDI/MDI-X configuration eliminates the need for cross-over cables when connecting
to another device, such as a hub. The algorithm is controlled via settings in the Ethernet PHY
Management Register 24 - MDI/MIDIX Control (MR24). Refer to page 479 for additional details
about these settings.
16.2.3.5 Power Management
The PHY has two power-saving modes:
■ Power-Down
■ Receive Power Management
Power-down mode is activated by setting the PWRDN bit in the MR0 register. When the PHY is in
power-down mode, it consumes minimum power. While in the power-down state, the Ethernet
Controller still responds to management transactions.
Receive power management (RXCC mode) is activated by setting the RXCC bit in the MR16 register.
In this mode of operation, the adaptive equalizer, the clock recovery phase lock loop (PLL), and all
other receive circuitry are powered down. As soon as a valid signal is detected, all circuits are
automatically powered up to resume normal operation. Note that the RXCC mode is not supported
during 10BASE-T operation.
16.2.3.6
LED Indicators
The Ethernet Controller supports two LED signals that can be used to indicate various states of
operation. These signals are mapped to the LED0 and LED1 pins. By default, these pins are
configured as GPIO signals (PF3 and PF2). For the PHY layer to drive these signals, they must be
reconfigured to their alternate function. See “General-Purpose Input/Outputs (GPIOs)” on page 180
for additional details. The function of these pins is programmable via the PHY layer Ethernet PHY
Management Register 23 - LED Configuration (MR23). Refer to page 478 for additional details on
how to program these LED functions.
16.2.4
Interrupts
The Ethernet Controller can generate an interrupt for one or more of the following conditions:
■ A frame has been received into an empty RX FIFO
■ A frame transmission error has occurred
■ A frame has been transmitted successfully
■ A frame has been received with inadequate room in the RX FIFO (overrun)
■ A frame has been received with one or more error conditions (for example, FCS failed)
■ An MII management transaction between the MAC and PHY layers has completed
■ One or more of the following PHY layer conditions occurs:
April 05, 2010
439
Texas Instruments-Production Data