dp83261 National Semiconductor Corporation, dp83261 Datasheet - Page 74

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

7 0 Signal Descriptions
PH DATA Request
The Ring Engine generates the 10 bit byte stream as defined in Table 7-2 Note that all symbol pairs are either control or data
symbol pairs Mixed data control symbol pairs are never generated or repeated by the Ring Engine
Where
The Ring Engine can repeat the RS RT and ST symbol pairs but does not create them
PRP
PRC
PRD(7 – 0) PHY Request Data (7 – 0)
PHY Request Parity bit parity for all symbol pairs is ODD
PHY Request control bit
0
1
e
e
Value
0
1
254
255
JK
II
RR
RS
RT
SS
SR
ST
TR
TS
TT
l
l
data byte
control byte
PRP
1
0
0
1
0
0
0
1
0
0
1
1
0
1
0
(Continued)
TABLE 7-2 Internal PHY Request Coding
PRC
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
PRD(7 – 4)
0000
0000
1111
1111
1101
1010
0110
0110
0110
0111
0111
0111
0101
0101
0101
74
PRD(3 – 0)
0000
0001
1110
1111
1101
1010
0110
0111
0101
0111
0110
0101
0110
0111
0101
Data Symbol Pair
Data Symbol Pair
Data Symbol Pair
Data Symbol Pair
Start Delimiter
Idle Symbols
Frame Status
Frame Status
Frame Status
Frame Status
Frame Status
Frame Status
Ending Delimiter
Ending Delimiter
Ending Delimiter
Type