Packet fill can be enabled
(CPSW_PN_EST_CONTROL_REG[8] EST_FILL_EN = 1h) to occur in the fetch count time
associated with a fetched zero allow. The intention with fill is that a smaller
packet on a non-timed priority might be able to be inserted on the wire during the
wire clear time which would increase wire utilization. Fill is intended to be used
with either only express priorities in the previous non-zero fetched allow, or only
prempt priorities in the previous non-zero fetched allow but not both. Fill must be
configured to ensure that any fill packet does not conflict with the timed express
packet allowed in the next fetch.
- Express fill:
- CPSW_PN_EST_CONTROL_REG[8] EST_FILL_EN is set and
- A fetch contains a
non-zero fetch count with a zero fetch allow, and
- The previous allow
contained only express priorities.
- The fetch count
loaded should be at least TBD clocks and the
CPSW_PN_EST_CONTROL_REG[25-16] EST_FILL_MARGIN should be at least
TBD clocks in Gigabit mode to ensure that the wire is
cleared for the timed express packet allowed in the next fetch.
- The fetch count
loaded should be at least TBD clocks and the
CPSW_PN_EST_CONTROL_REG[25-16] EST_FILL_MARGIN should be at least
TBD clocks in 10/100Mbps mode to ensure that the wire
is cleared for the timed express packet allowed in the next
fetch.
- Prempt fill:
- CPSW_PN_EST_CONTROL_REG[8] EST_FILL_EN is set and
- A fetch contains a
non-zero fetch count with a zero fetch allow, and
- The previous allow
contained only prempt priorities
- The fetch count
loaded should be at least TBD clocks in Gigabit mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.
- The fetch count
loaded should be at least TBD clocks in 10/100Mbps mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.
- Express non-fill:
- CPSW_PN_EST_CONTROL_REG[8] EST_FILL_EN is clear and
- The previous allow
contained only express priorities.
- The fetch count
loaded should be at least TBD clocks in Gigabit mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.
- The fetch count
loaded should be at least TBD clocks in 10/100Mbps mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.
- Prempt non-fill:
- CPSW_PN_EST_CONTROL_REG[8] EST_FILL_EN is clear and
- The previous allow
contained only prempt priorities.
- The fetch count
loaded should be at least TBD clocks in Gigabit mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.
- The fetch count
loaded should be at least TBD clocks in 10/100Mbps mode to
ensure that the wire is cleared for the timed express packet allowed
in the next fetch.