dp83261 National Semiconductor Corporation, dp83261 Datasheet - Page 58

• Manufacturer Part Number: dp83261
• Description: Bmac Device Fddi Media Access Controller
• Manufacturer: National Semiconductor Corporation

6 0 Control Information
Maximum Token Rotation Time (TMAX)
The Maximum Token Rotation Time (TMAX) denotes the maximum Target Token Rotation Time supported by this station
TMAX is stored as a 4-bit value that is expanded to a binary exponential value Bits 7 – 4 are ignored during write operations and
are always read as Zero
TMAX has a maximum value of 1 34 seconds with a threshold of 40 96
to One) TMAX is set to the value of Ch which corresponds to 167 772 ms the default specified by the FDDI MAC Standard
ACCESS RULES
TMAX
Address
93h
Zero
D7
Always
Read
Zero
D6
(Continued)
Zero
Stop Mode
D5
TMAX(0 – 3)
Write
D
0
1
2
3
4
5
6
7
8
9
A
B
C
E
F
Zero
D4
58
163 84 ms
327 68 ms
655 36 ms
1 3107 ms
2 6214 ms
5 2429 ms
10 486 ms
20 972 ms
41 943 ms
83 886 ms
167 77 ms (default)
335 54 ms
671 09 ms
1 3422s
40 96 ms
81 92 ms
TMAX(3)
D3
Time
c
2
TMAX
ms On a Master Reset (Function MARST set
TMAX(2)
D2
TMAX(1)
D1
TMAX(0)
D0