1 set_link_rate command, 2 open_channel command – NEC Network Controller uPD98502 User Manual
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CHAPTER 4 ATM CELL PROCESSOR
258
Preliminary User’s Manual S15543EJ1V0UM
4.7.1 Set_Link_Rate command
This command is used to set the link rate of ATM PHY interface. After initializing ATM Cell Processor, this
command has to be issued once, before any packet is transmitted.
Figure 4-18. Set_Link_Rate Command
[Set_Link_Rate command]
CMR
0
1
1
1
0
PHY No.
Link Rate
31 30
2
9
28 27 26
20 19
16 15
0
PHY No.
PHY Number.
Link Rate
Actual Link Rate is inserted in this field. The format of the rate is following.
2
e
(1 + m/512)*nz cells/sec
Re-
served
nz
e
m
15
14
13
9
8
0
4.7.2 Open_Channel command
This command is used to open a new channel to be used for a send or receive operation. When the channel is
opened, ATM Cell Processor reserves the area for the VC table in Work RAM and returns the VC Number as an
indication.
The indication that ATM Cell Processor returns for this command is of the following format:
Figure 4-19. Open_Channel Command and Indication
[Open_Channel command]
CMR
0
1
0
0
0
0
31 30 29 28 27 26 25
0
[Open_Channel command Indication]
CMR
Undefined
VC Number
0
31
18 17
6
5
0
VC Number
VC Number of the opened channel. If no more new VCs can be opened, VC Number in the
indication is set to 0.