AL2100-DS00-R datasheet(18/52 Pages) BOARDCOM

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AL2100

Preliminary Data Sheet

11/11/02

Broa d c om Co rp o r a ti o n

Page 10

Serial Management Interface

Document

AL2100-DS01-405-R

LED CONFIGURATION

The LED interface is fully configurable via the common register setting. See Table 3.

Each LED has two 16-bit registers that define the operation. See ”Common Registers” on page 27 for details.

SERIAL MANAGEMENT INTERFACE

MII management access is performed via pin MDC and MDIO. The MDC input pin is SCHMTT triggered to avoid noise on

this bused signal.

The PHY’s internal registers are accessible only through the MII 2-wire Serial Management Interface (SMI). MDC is a clock

input to the PHY, which is used to latch in or out data and instructions for the PHY. The clock can run at any speed from DC

to 25 MHz. MDIO is a bi-directional connection used to write instructions to, write data to, or read data from the PHY. Each

data bit is latched either in or out on the rising edge of MDC. MDC is not required to maintain any speed or duty cycle,

provided no half cycle is less than 20 ns, and that data is presented synchronous to MDC.

MDC and MDIO are a common signal pair to all PHYs on a design. Therefore, each PHY must have its own unique physical

address. The physical address of the PHY is set by using the pins defined as PHYAD[4:0]. These input signals are strapped

externally, and sampled as reset is negated. At idle, the PHY is responsible to pull the MDIO line to a high state. Therefore,

a 1K Ohm resistor is required to connect the MDIO line to VCC.

PHY ADDRESSES

Two PHY addresses are taken under AL2100 mode. One is PHYAD [4:0], and the other is PHYAD [4:0] + 1. The first one is

for twisted-pair PHY; the second is for fiber PHY.

The PHY addresses are set via the PHYAD4, PHYAD3, PHYAD2, PHYAD1, and PHYAD0 signals.

CLOCK SOURCE

The clock source for this chip is from the XI signal.

In normal operation mode (media converter), the XI signal is connected to a 25 Mhz, 50 PPM Oscillator or XI and XO signals

are connected to a 25 MHz, 50 PPM Crystal.

Table 3: Events for LED Operation

Bit

Events Description

7RxAct_FX

6Link_FX

5Link_TP

DUPLEX_TP

3TxAct_TP

Remote_fault

1N/A

0RxAct_TP

AL2100-DS00-R Datasheet(PDF) 18 Page - Broadcom Corporation.

AL2100-DS00-R Datasheet(HTML) 18 Page - Broadcom Corporation.

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