Cirrus Logic EP93 Series User Manual page 467

0x8002_0040
Default:
0x0000_0000
Definition:
Defines the earliest time the host controller should start processing the
periodic list.
Bit Description:
RSVD:
PS:
HcLSThreshold
31 30 29 28
15 14 13 12
RSVD
Address:
0x8002_0044
Default:
0x0000_0628
Definition:
Contains a value used by the host controller to determine whether to commit
to the transfer of a maximum 8-byte LS packet before EOF.
Bit Description:
RSVD:
LST:
DS785UM1
Reserved. Unknown During Read.
PeriodicStart. After a hardware reset, this field is cleared.
This is then set by HCD during the HC initialization. The
value is calculated roughly as 10% off from HcFmInterval.
A typical value will be 0x03E67. When HcFmRemaining
reaches the value specified, processing of the periodic
lists will have priority over Control/Bulk processing. HC will
therefore start processing the Interrupt list after completing
the current Control or Bulk transaction that is in progress.
27 26 25 24
RSVD
11 10 9 8
Reserved. Unknown During Read.
LSThreshold. This field contains a value which is
compared to the FrameRemaining field prior to initiating a
Low Speed transaction. The transaction is started only if
FrameRemaining >= this field. The value is calculated by
HCD with the consideration of transmission and setup
overhead.
Copyright 2007 Cirrus Logic
Universal Serial Bus Host Controller
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LST
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