Add_Buffers Command - NEC uPD98502 User Manual

4.7.5 Add_Buffers command

The Add_Buffers command is used to add unused buffer directories to a single receive free buffer pool.
In this command, when ATM Cell Processor detects some errors, it writes E bit in A_CMR. This command has the
following format:
[Add_Buffers command]
CMR
0 1 1 0 1
31 30 29 28 27 26 25
CER
31
[Add_Buffers command indication]
CMR
0 1 1 0 1 0
31 30 29 28 27 26 25 24 23
Add_Buffers command
Pool No.
Number of Buffer Directories
Buffer Directory Pointer
Add_Buffers command indication
E
Pool No.
Number of Buffer Directories
CHAPTER 4 ATM CELL PROCESSOR
Figure 4-22. Add_Buffers Command
0 Pool No.
21 20
Buffer Directory Pointer
E 0 Pool No.
21 20
Number of the pool to which buffer directories are to be added. Since ATM Cell
Processor supports only 8 pools (0 to 7), Bit 19 and 20 should be set to a '0'.
Number of new buffer directories to be added
Start address of the first buffer directory in the list of new buffer directories to be
added
Error bit. If detects an error, sets this bit to a '1'. When V
command, this bit has to be a '0'. The possible error is the number of buffer
directories after this command is executed exceeds 65535.
Number of the pool to which new buffer directories are just added
Number of new buffer directories just added
Preliminary User's Manual S15543EJ1V0UM
Number of Buffer Directories
16 15
Number of Buffer Directories
16 15
0
0
0
4120A issues this
R
261