dp83251 National Semiconductor Corporation, dp83251 Datasheet - Page 28

• Manufacturer Part Number: dp83251
• Description: Player Device Fddi Physical Layer Controller
• Manufacturer: National Semiconductor Corporation

D3 D4
D5
D6
D7
5 0 Registers
CURRENT TRANSMIT STATE REGISTER (CTSR) (Continued)
Bit
Symbol
IC0 IC1
SE
PRDPE
RES
(Continued)
Injection Control
overwrite data from the Smoother Repeat Filter Encoder and Transmit Modes
IC0 is the only bit of the register that is automatically cleared by the PLAYER device after the One Shot
Injection is executed The automatic clear of IC0 during the One Shot mode can be interpreted as an
acknowledgment that the One Shot has been completed
SMOOTHER ENABLE
Note Once the counter has started it will continue to count irrespective of the incoming symbols with the exception of a
JK symbol pair This bit should be enabled for interoperable operation
PHY REQUEST DATA PARITY ENABLE
RESERVED Reserved for future use
Note Users are discouraged from using this bit The reserved bit is set to 1 during the reset process It may be set or
cleared without any effects to the functionality of the PLAYER device
0 Disables PHY Request Data parity
1 Enables PHY Request Data parity
0 Disables the Smoother
1 Enables the Smoother
When enabled the Smoother can redistribute Idle symbol pairs which were added or deleted by
the local or upstream receivers
k
0 1
l
These bits select one of the 4 injection modes The injection modes
IC1
0
0
1
1
28
Description
IC0
0
1
0
1
No Injection The normal transmission of
incoming PHY Request data (i e symbols are
not injected)
One Shot In one shot mode Injection
Symbol Register A (ISRA) and Injection
Symbol Register B (ISRB) are injected n
symbol pairs after a JK where n is the
programmed value of the Injection Count
Register (IJCR) If IJCR is set to 0 the JK
symbol pair is replaced by ISRA and ISRB
Once the One Shot is executed the PLAYER
device automatically sets IC0 to 0 thereby
returning to normal transmission of data
Periodic In Periodic mode Injection Symbol
Register A (ISRA) and Injection Symbol
Register B (ISRB) are injected every (n
symbol pair where n is the programmed
value of the Injection Count Register (IJCR)
If IJCR is set to 0 all data symbols are
replaced with ISRA and ISRB
Continuous In Continuous mode all data
symbols are replaced with Injection Symbol
Register A (ISRA) and Injection Symbol
Register B (ISRB)
a
1)th