ACC Utilities Reference Guide

TTGEN - ZCOM System Table Generator
Creating the TTGEN Configuration File
Chapter 238
Interface-Table
Total number of interface tables in this configuration. Each entry in the
“Interface-Definition” section uses one interface table. The interface
tables are numbered from 0, hence this value must be at least one
greater than the number of ACC card statements in Interface-Definition
section. That is, it must be larger than the largest interface card number
defined. You may want to specify a larger value to allow for
programmatic additions while the system is running (using the Dynamic
System Configuration functions). The valid range of values is 1…64
(ZCOM_MAXIFT in /opt/acc/include/zcom/zcomsys.h).
Buffer-Pool
Block of memory (free buffer area), from which all buffers are allocated to
the ZCOM sub-system. The range of valid values is 1024…2147483645
(0x7FFFFFF, ZCOM_MAXBPOOL in
/opt/acc/include/zcom/zcomsys.h). Default is 3 Mbytes. Must be a
multiple of 4. The kernel memory plus the ZCOM memory size cannot
exceed available physical memory. The recommended minimum is 200
Kbyte (e.g., for a small test environment). The buffer pool plus the size of
the ZCOM tables should not exceed the amount of memory gen’d into the
kernel for the ZCOM subsystem (controlled through the zcom_mem_size
parameter in the system file). For a production environment, use the
following method to estimate the required Buffer-Pool size:
BUFFER-POOL size = <Card> x <Rate> x <Time> x (<Length> + 200) x 1.5
<Card> number of ACC cards in system
<Rate> maximum number of messages per second per ACC
card
<Time> average turn-around time, in seconds, for one message
(including transmission time). This also depends on
SPU processing power. For most systems, 5 seconds
should be adequate.
<Length> average message length
200 is the memory overhead per message (in bytes).
1.5 is the scaling factor to allow for usable gaps in buffer pool