5222-DS02-R datasheet(51/76 Pages) BOARDCOM

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Preliminary Data Sheet

BCM5222

7/20/04

Broadcom Corporation

Document 5222-DS02-405-R

10BASE-T Auxiliary Error and General Status Register

Page 39

MANCHESTER CODE ERROR

Indicates that a Manchester code violation was received. This bit is only valid during 10BASE-T operation.

END OF FRAME ERROR

Indicates that the End Of Frame (EOF) sequence was improperly received, or not received at all. This error bit is only valid

during 10BASE-T operation.

AUTO-NEGOTIATION INDICATION

This read-only bit indicates whether auto-negotiation has been enabled or disabled on the BCM5222. A combination of a 1

in bit 12 of the Control register and a logic 1 on the ANEN input pin is required to enable auto-negotiation. When auto-

negotiation is disabled, bit 15 of the Auxiliary Mode register returns a 0. At all other times, it returns a 1.

FORCE 100/10 INDICATION

This read-only bit returns a value of 0 when one of following two cases is true:

•

The ANEN pin is low AND the F100 pin is low. (or)

•

Bit 12 of the Control register has been written 0 AND bit 13 of the Control register has been written 0.

When bit 2 of the Auxiliary Control register is 0, the speed of the chip is 10BASE-T. In all other cases, either the speed is

not forced (auto-negotiation is enabled), or the speed is forced to 100BASE-TX.

SPEED INDICATION

This read-only bit shows the true current operation speed of the BCM5222. A 1 bit indicates 100BASE-TX operation, while

a 0 indicates 10BASE-T. While the auto-negotiation exchange is performed, the BCM5222 is always operating at 10BASE-

T speed.

FULL-DUPLEX INDICATION

This read-only bit returns a 1 when the BCM5222 is in full-duplex mode. In all other modes, it returns a 0.

5222-DS02-R 数据表(PDF) 51 Page - Broadcom Corporation.