AM79C864AKCW AMD [Advanced Micro Devices], AM79C864AKCW Datasheet - Page 36

• Manufacturer Part Number: AM79C864AKCW
• Description: Physical Layer Controller With Scrambler (PLC-S)
• Manufacturer: AMD [Advanced Micro Devices]

continue for T_SCRUB length of time and then enter the
REMOVED state.
PCI Operation for Class S Type Station
For a Class S type station, the PCI Operation is same as
above with one exception. Normally, for a Non-Class S
type station, PCI will be in REMOVED state at reset, but
for a Class S type station, PCI will be in the INSERTED
state. Thus, before entering INSERT_SCRUB or after
leaving REMOVE_SCRUB, rather than putting the
PLC-S in the bypass mode, PHY_INVALID is output on
RX 9–0.
PCI Operation in MAINT State
When the PCM state machine is in the MAINT state, the
PCI state machine does not control the above functions.
In this state all the data paths are under the control of
software. Software controls the data paths via several
control bits in the PLC_CNTRL_A register. Software
can also override the PCI functions when the PCM state
machine is not in the MAINT state by setting the
CONFIG_CNTRL bit in the PLC_CNTRL_B register.
PCI State Machine
The function of the PCI State Machine is described in
Table 14 and Figure 3.
3-38
AMD
The SUPERNET 2 Family for FDDI 1994 Data Book
P R E L I M I N A R Y
Note:
User cannot disable PCI.
State
PCI0
(REMOVED)
PCI1
(INSERT SCRUB)
PCI2
(REMOVE SCRUB) A transition is made to REMOVED (or to
PCI3
(INSERTED)
Table 14. PCI State Description
Description
In this state the PCI causes PLC-S to be
bypassed. A transition is made to
INSERT_SCRUB when SET_SC_JOIN
signal is asserted. A transition is made to
INSERTED if CLASS_S or PCM_MAINT
is set.
In this state scrubbing is performed.
A transition is made to INSERTED after
T_SCRUB length of time.
In this state scrubbing is performed.
INSERTED if CLASS_S is set) after
T_SCRUB length of time.
In this state scrubbing has completed and
the data paths exists between the PDT/PDR
and the MAC. A transition is made to the
REMOVE_SCRUB state if the START_
SCRUBBING signal is asserted. A transition
is made to the INSERT_SCRUB state if the
SET_SC_JOIN signal is asserted (will only
occur if CLASS_S is set).