AM79C973 Datasheet, PDF (202/304 Pages) Advanced Micro Devices – PCnet™-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY

PRELIMINARY
ANR18: Descrambler Resynchronization Timer
Register (Register 18)
Descrambler Resynchronization Timer Register
(shown in Table 51) allows the user to program the time
it takes for the descrambler to start the resynchroniza-
tion process. This is to ensure that the Descrambler re-
synchronizes itself to the next IDLE symbol stream
after it receives a packet of excessive length. This reg-
ister should be programmed as described in the Table
51. The programmed timer value should always be
greater than the length of the maximum size packet in
normal operation.
Table 51. ANR18: Descrambler Resynchronization Timer (Register 18)
Reg Bits
Name
Description
Read/
Write
Default
Value
Soft
Reset
18 15-0
Descrambler Resynch Timer
Each bit indicates 4 clocks, or 160
ns. The count decrements from a
default value of 1 ms or an initial
value loaded by the user. This
counter provides a maximum timer
value of 10.5 ms.
R/W
000110000
1101010
(Note 1)
0001100
0011010
10
(Note 1)
Note:
1. The corresponding time to this setting is 1ms.
ANR19: PHY Management Extension Register
(Register 19)
Table 52 contains the PHY Management Extension
Register (Register 19) bits.
Reg Bits
19 15:6
19
5
Table 52. ANR19: PHY Management Extension Register (Register 19)
Name
Description
Read/Write
Default Value
Reserved
Write as 0, ignore on read.
RO
0
1 = last management frame
Mgmt Frame
Format
was invalid (opcode error, etc.);
0 = last management frame
RO
0
was valid.
19 4-0
PHY Address
PHY Address defaults to
11110.
RO
11110
ANR24: Summary Status Register (Register 24)
The Summary Status register is a global register con-
taining status information. This register is Read/Only
and represents the most important data which a single
register access can convey. The Summary Status reg-
ister indicates the following: Link Status, Full Duplex
Status, Auto-Negotiation Alert, and Speed. See Table
53.
Soft Reset
0
0
Retains
Previous
Value
202
Am79C973/Am79C975