ibm3206k0424 ETC-unknow, ibm3206k0424 Datasheet - Page 76

• Manufacturer Part Number: ibm3206k0424
• Description: Ibm Processor For Network Resources
• Manufacturer: ETC-unknow

IBM3206K0424
IBM Processor for Network Resources
ABR Code Variables Definitions
Packet Header
Page 76 of 676
Current_transport_stream_packet
Packets_per_AAL5_frame #
Current_Blocking_Count
seg_prc_Entry_point #
Fixed_Blocking_size #
segmentation_pointer
xmt_cmp_evt_mod
ATM_header #
threshold_1&2
minimum_rate
backward_ptr
current_CRC
buffer_offset
explicit_rate
current_rate
Field Name
conn_suss
xmit_stat1
xmit_stat2
drop
This bit is used on ABR connections to suspend transmission. It should be initialized to ‘0’.
These two bits are used to indicate which physical drop will be used for this connection. Traffic can
be scheduled on up to four drops.
This field contains the offset into the buffer that the transmit data starts.
This two-bit field can optionally (based on a bit in the SEGBF control register) be logically ORed with
bits 8-7 of a transmit complete buffer event when it is generated by the segmentation logic. This field
will only be ORed when buffer address events are being generated. It will have no affect when LCD
addresses are being enqueued when a transmit complete event occurs.
This four-bit field is loaded into the instruction pointer for both the LCD update processor and the cell
generation processor when a cell opportunity occurs for the LCD. The value loaded into this field
defines what type of cell will be generated by the segmentation logic. Possible types include raw 48-
and 52-byte cells, AAL5 cells, switch bound cells (48-byte payload), extended switch bound cells
(54-byte payload), and frame-based cells. The actual values that are associated with each type of
cell will be defined at a later time.
This field contains the first four bytes of the ATM header.
This field contains a pointer to the next data to be transmitted. In normal operation, this field is initial-
ized by the cell scheduler when a new frame is queued for segmentation.
This field contains the CRC as it is being built.
This eight-bit field contains the current count of four-byte values that have been assembled into cells
and sent out on this LCD for all fix block or MPEG AAL types. Other than initialization, this field
should only be accessed by the hardware.
This eight-bit field should be initialized by the software to contain the number of four-byte values that
constitute a packet. For MPEG2, this register should be set to x’2F’ (4 • x’2F’ = 188 byte transport
stream packet).
This eight-bit field contains the number of the current transport stream packet that is being seg-
mented. Other than initialization, this field should only be accessed by the hardware.
This eight-bit field should be initialized by the software to indicate how many packets should be con-
catenated into an AAL5 frame.
This 16-bit field contains the explicit cell rate as defined for ABR traffic on this LCD.
This 16-bit field contains the current cell rate as defined for ABR traffic on this LCD.
This 16-bit field contains the minimum cell rate as defined for ABR traffic on this LCD.
When software needs to send a backward RM cell, this 32-bit field should be updated with the
address of a buffer that contains the desired backward RM cell. After the segmentation logic trans-
mits the cell, this field is cleared by the hardware.
This 32-bit field contains a count of one of three things: the total number of user cells that have been
sent on this LCD, the total number of bytes that have been sent on this LCD, or the total number of
frames that have been sent on this LCD. This field should zeroed when the connection is initialized.
An event will be generated when this count wraps.
This 32-bit field contains a count of one of three things: the total number of user cells that have been
sent on this LCD, the total number of bytes that have been sent on this LCD, or the total number of
frames that have been sent on this LCD. This field should be zeroed when the connection is initial-
ized. An event will be generated when this count wraps.
These fields are compared to the upper 24 bits of the bytes_queued field to determine when a
threshold is crossed and the POOL ID for the received LCD should be changed.
(Page 3 of 4)
Field Description
pnr25.chapt03.01
August 14, 2000
Preliminary