Broadcom BCM5722 - Table 546: 100-BASE-X Auxiliary Control Register (Address 16 D, 10 H)

BCM5722 Programmer’s Guide
10/15/07
Broadcom Corporation
Page 493 Transceiver Registers (BCM5906/BCM5906M) Document 5722-PG101-R
100BASE-X Auxiliary Control Register
Transmit Disable
The transmitter is disabled by writing a 1 to bit 13 of MII register 10h. The transmitter output (TD±) is forced into a high
impedance state.
Bypass 4B5B Encoder/Decoder
The 4B5B encoder and decoder are bypassed by writing a 1 to bit 10 of MII register 10h. The transmitter sends 5B codes
from the TXER and TXD signals directly to the scrambler. TXEN must be active and frame encapsulation (insertion of J/K
and T/R codes) is not performed. The receiver places descrambled and aligned 5B codes onto the RXER and RXD signals.
CRS is asserted when a valid frame is received.
Bypass Scrambler/Descrambler
The stream cipher function is disabled by writing a 1 to bit 9 of MII register 10h. The stream cipher function is re-enabled by
writing a 0 to this bit.
Bypass NRZI Encoder/Decoder
The NRZI encoder and decoder can be bypassed by writing a 1 to bit 8 of MII register 10h, causing 3-level NRZ data to be
transmitted and received on the cable. Normal operation (3-level NRZI encoding and decoding) is re-enabled by writing a
0to this bit.
Bypass Receive Symbol Alignment
Receive symbol alignment is bypassed by writing a 1 to bit 7 of MII register 10h. When used in conjunction with the bypass
4B5B encoder/decoder bit, unaligned 5B codes are placed directly on the RXER and RXD signals.
Baseline Wander Correction Disable
The baseline wander correction circuit is disabled by writing a 1 to bit 6 of MII register 10h. The PHY corrects for baseline
wander on the receive data signal when this bit is cleared.
Table 546: 100-BASE-X Auxiliary Control Register (Address 16d, 10h)
Bit Name R/W Description Default
15 Next Page RO 1 = Additional Next Page(s) follows
0 = Last page
0
14 Reserved - - 0
13 Message Page RO 1 = Message page 0 = Unformatted page 0
12 Acknowledge 2 RO 1 = Will comply with message
0 = Cannot comply with message
0
11 Toggle RO 1 = Previous value of the transmitted link code word equaled logic 0
0= Previous value of the transmitted link code word equaled logic 1
0
10:0 Message/Unformatted
Code Field
RO - 0
R/W = Read/Write, RO = Read only, SC = Self Clear, LL = Latched Low, LH = Latched High, LL and LH Clear after read
operation. Use default values of reserved bit(s) when writing to reserved bit(s).