am79c864a Advanced Micro Devices, am79c864a Datasheet - Page 12

• Manufacturer Part Number: am79c864a
• Description: Physical Layer Controller With Scrambler Plc-s
• Manufacturer: Advanced Micro Devices

RRSCLK
Reserved (Input)
This pin should be connected to VSS.
Control and Status Signals
EBFERR
Elasticity Buffer Error (Output, Active High)
EBFERR indicates when an overflow or underflow con-
dition occurs in the Elasticity Buffer.
ENCOFF
Encoder Off (Input, Active High)
The ENCOFF signal turns off the encoding and decod-
ing function of the PLC-S. This allows for the transmis-
sion of any symbol, including invalid symbols for
diagnostic purposes.
LSR 2–0
Line State Register (Output)
The LSR 2–0 signals directly output the LINE_ST field of
the PLC_STATUS_A register to ring test and monitor
equipment.
3-14
AMD
LSR 2–0
000
001
010
011
100
101
110
111
Description
Noise Line State (NLS)
Active Line State (ALS)
Undefined
Idle Line State (ILS4 –
achieved after 4 Idle symbols)
Quiet Line State (QLS)
Master Line State (MLS)
Halt Line State (HLS)
Idle Line State (ILS16 –
achieved after 16 Idle symbols)
The SUPERNET 2 Family for FDDI 1994 Data Book
P R E L I M I N A R Y
ULSB
Unknown Line State (Output)
The ULSB signal directly outputs the UNKN_LINE_ST
bit of the PLC_STATUS_A register to ring test and moni-
tor equipment.
SCRM
Scrambler Enable (Input)
This pin when held high will enable the Stream Cipher
Scrambling/Descrambling function. If this pin is held
low, then bit 0 of PLC_CNTRL_C Register determines if
Stream Cipher Scrambling/Descrambling function is
enabled.
Power and Ground
VDD
Power (Inputs)
The VDD pins supply +5 V to the device.
VSS
Ground (Input)
The VSS pins ground the device.