FireWire
PIKE Technical Manual
V5.0.0
32
In case of 1394b no gaps are needed due to parallel arbitration, handled by
bus owner supervisor selector (BOSS) (see the following diagram). Whereas
1394a works in half duplex transmission, 1394 does full duplex transmission.
Additional devices may be added up to the overall capacity of the bus, but
throughput at guaranteed minimum service levels is maintained for all
devices with an acknowledged claim on the bus. This deterministic feature is
a huge advantage for many industrial applications where robust performance
is required. Such is the case when it is not acceptable to drop images within
a specific time interval.
Figure 2: 1394a data transmission
Figure 3: 1394b data transmission
Cycle Sync: 1394b
Parallel arbitration, handled by BOSS, can eliminate gaps
