DP83266VF National Semiconductor, DP83266VF Datasheet - Page 80

• Manufacturer Part Number: DP83266VF
• Description: IC MEDIA ACSS CTRL INTF 160PQFP
• Manufacturer: National Semiconductor

Specifications of DP83266VF

• Applications: *
• Voltage - Supply: 4.75 V ~ 5.25 V
• Package / Case: 160-BFQFP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Interface: -
• Other names: *DP83266VF

7 0 Control Information
7 6 1 Asynchronous Priority Threshold (THSH1)
The Ring Engine currently supports one Asynchronous Priority Threshold in addition to the default threshold at TTRT The
Asynchronous Priority Threshold is used in a magnitude comparison with THT when an Asynchronous Priority Request is
presented to the MAC Request Interface
Bits 7 –4 are always written to Zero and are always read as Zero
When more than one threshold is used the users of THSH1 have the lowest priority All asynchronous transmissions are limited
by TTRT If the Late Flag is set no frames may be transmitted regardless of the value of the Asynchronous Priority Threshold
Access Rules
Register Bits
Warning The default value may not be appropriate for all values of TNEG In some cases this could result in a request that is NEVER serviced
THSH1
Address
THSH1(3 –0)
087h
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
Zero
D7
Always
Read
Time remaining in THT when
Zero
token becomes unusable
D6
Stop Mode
163 84
327 68
655 36
1 3107 ms
2 6214 ms
5 2429 ms
10 486 ms
20 972 ms
41 943 ms (default)
83 886 ms
167 77 ms
335 54 ms
10 24
20 48
40 96
81 92
Write
Zero
D5
s
s
s
s
s
s
s
(Continued)
Zero
D4
THSH(3)
D3
80
THSH(2)
D2
THSH(1)
D1
THSH(0)
D0