CS8952 datasheet(74/82 Pages) CIRRUS

74 / 82 page

CS8952

CrystalLAN™ 100BASE-X and 10BASE-T Transceiver

BP4B5B - Bypass 4B5B Coders. Input, Pin 56.

When driven high during power-up or reset, the transmit 4B5B encoder and receiver 5B4B decoder are

bypassed. Five-bit code groups are output and input on pins RXD[4:0] and TXD[4:0].

The 4B5B Coders may also be bypassed under software control through bit 14 of the Loopback,

Bypass, and Receiver Error Mask Register (address 18h).

At power-up or at reset, the value on this pin is latched into bit 14 of the Loopback, Bypass and

Receiver Error Mask Register (address 18h). This pin includes a weak internal pull-down (> 20 K

Ω), or

the value may be set by an external 4.7 K

Ω pull-up or pull-down resistor.

BPALIGN - Bypass Symbol Alignment. Input, Pin 52.

When driven high during power-up or reset, the following blocks are bypassed: 4B5B encoder, 5B4B

decoder, scrambler, descrambler, NRZI encoder, and NRZI decoder. Five-bit code groups are output and

input on pins RXD[4:0] and TXD[4:0]. The receiver will output five-bit data with no attempt to identify

code-group boundaries; therefore, the data in one RXD[4:0] word may contain data from two code

groups.

Symbol alignment may also be bypassed under software control through bit 12 of the Loopback,

Bypass, and Receiver Error Mask Register (address 18h).

At power-up or at reset, the value on this pin is latched into bit 12 of the Loopback, Bypass and

Receiver Error Mask Register (address 18h). This pin includes a weak internal pull-down (> 20 K

Ω), or

the value may be set by an external 4.7 K

Ω pull-up or pull-down resistor.

BPSCR - Bypass Scrambler. Input, Pin 62.

When driven high during power-up or reset, the scrambler and descrambler is bypassed and NRZI FX

mode is selected.

The 100BASE-FX mode may also be entered under software control through bit 13 of the Loopback,

Bypass, and Receiver Error Mask Register (address 18h).

At power-up or at reset, the value on this pin is latched into bit 13 of the Loopback, Bypass and

Receiver Error Mask Register (address 18h). This pin includes a weak internal pull-down (> 20 K

Ω), or

the value may be set by an external 4.7 K

Ω pull-up or pull-down resistor.

CS8952 Datasheet(PDF) 74 Page - Cirrus Logic