ICS1893 datasheet(115/152 Pages) ICST

115 / 152 page

Chapter 9

Pin Diagram, Listings, and Descriptions

ICS1893 Rev C 6/6/00

June, 2000

115

ICS1893 - Release

TXEN

Input

Transmit Enable.

In MII mode:

• The ICS1893 samples its TXEN signal to determine when data is

available for transmission. When TXEN is asserted, the ICS1893

begins sampling the data nibbles on the transmit data lines TXD[3:0]

synchronously with TXCLK. The ICS1893 then transmits this data over

the media.

• Following the de-assertion of TXEN, the ICS1893 terminates

transmission of nibbles over the media.

TXER

Input

Transmit Error.

When the MAC/Repeater Interface is in:

• 10M MII mode, TXER is not used.

• 100M MII mode:

– The ICS1893 synchronously samples its TXER signal on the rising

edges of its TXCLK signal.

– The assertion of TXER by the MAC/repeater causes the ICS1893 to

transmit an Invalid Symbol.

– the Invalid Error Code Test bit (bit 16.2) is set to logic one, the 5-bit

symbol shown in the Invalid Error Code Translation Table (Table

8-17) is used instead of the normal 4B/5B encoding described in the

ISO/IEC specification.

Note: The Invalid Symbol used for this function is the HALT symbol,

which is substituted for the transmit nibble received from the

MAC/repeater whenever the TXER is asserted.

Table 9-5.

MAC/Repeater Interface Pins: Media Independent Interface (MII) (Continued)

Name

Number

Type

Pin Description

ICS1893 Datasheet(PDF) 115 Page - Integrated Circuit Systems