ICS1892Y-14 datasheet(27/148 Pages) ICST

27 / 148 page

Chapter 6

Interface Overviews

ICS1892, Rev. D, 2/26/01

February 26, 2001

ICS1892

6.3

10M Serial Interface

When the Mac/Repeater Interface is configured as a 10M Serial Interface, the ICS1892 and the

MAC/repeater exchange a framed, serial bit stream along with associated control signals. The 10M Serial

Interface configuration is ideally suited to applications that already incorporate a serial 10Base-T MAC with

a standard ‘7-wire’ interface. The ICS1892 MAC/Repeater Interface can be configured for 10M Serial

Interface operations, as determined by ICS1892 configuration functions. When the HW/SW pin is set for:

• Hardware mode, the 10M Serial Interface is selected when the following are true:

– The MII/SI input pin is logic one (that is, the selection is for a Serial Interface).

– The 10/100SEL input pin is logic zero (that is, the selection is for 10M operations).

– The 10/LP input pin is logic zero

• Software mode, the 10M Serial Interface is selected when the following are true:

– The MII/SI input pin is logic one (that is, the selection is for a Serial Interface).

– The Control Register Data Rate bit (bit 0.13) is logic zero (that is, the selection is for 10M operations).

– The 10/LP input pin is logic zero

Note:

In software mode, the 10/100SEL pin becomes an output that indicates the state of bit 0.13.

The 10M Serial Interface has two data paths: one for data transmission and one for data reception. Each

data path exchanges a serial bit stream with the MAC/repeater at a 10-MHz clock rate. A benefit of using

the 10M Serial Interface – in contrast to the 10M MII Interface – is a reduction in the bit latency through the

ICS1892. This reduction is attributed to the elimination of both parallel-to-serial and serial-to-parallel data

conversions.

The 10M Serial Interface consists of the following nine signals: 10TCLK, 10TXEN, 10TD, 10RCLK,

10RXDV, 10RD, 10CRS, 10COL, and LSTA. (When the ICS1892 MAC/Repeater Interface is configured for

10M Serial operations, both its default MII pin names and their associated functions are redefined. For

more information, see Section 9.2.4.3, “MAC/Repeater Interface Pins for 10M Serial Interface”.)

ICS1892Y-14 Datasheet(PDF) 27 Page - Integrated Circuit Systems