User's Manual

Datalogic Scanning, Inc
959 Terry Street
Eugene, Oregon 97402
Page 70 10/23/2009
Revision X2
Parameter for the IQ trim auto calibration routine.
Selects whether phase trimming is done as part of the IQ trim routine. If this is set to disabled then the
appropriate bits from PSKEY_IQ_TRIM are used.
Key Name Key Number Type Default Setting
PSKEY_HCI_HANDLE_FREEZE_PERIOD 0x0237 TIME 15 * SECOND
The default period in microseconds for which data reception on a HCI connection handle is maintained
after the corresponding connection has been removed.
Reception must be enabled for this additional period as stray late data may come from the host. The freeze
period should thus be sufficiently large for the host to realise that a HCI connection has been removed or
has failed.
Any data received during the period when the connection handle is frozen is diverted into a dummy buffer
and thus effectively discarded.
The value stored under this key is also the minimum time before a HCI connection handle can be re-
allocated for a new connection.
Maintaining a connection handle for this additional period consumes some of the chip's resources. Hence
creating and destroying connections rapidly relative to the freeze period will result in a resource leak. After
the number of currently frozen handles reaches a limit set by PSKEY_MAX_FROZEN_HCI_HANDLES
,
further attempts to create connections will be rejected.
(Type TIME is fundamentally a uint32. Value SECOND is 1000000.)
Key Name Key Number Type Default Setting
PSKEY_MAX_FROZEN_HCI_HANDLES 0x0238 uint16 20
The default number of frozen connection handles at which further connection requests will be refused.
After a connection has been removed, its hci handle is maintained active for a short period, defined by
PSKEY_HCI_HANDLE_FREEZE_PERIOD. Some resources are required to maintain the link active and
thus if connections are created and destroyed rapidly in relation to this period, resources will gradually be
consumed.
To prevent constraining the operation of any existing connections due to lack of memory, further
connection requests will be rejected when the number of currently frozen handles reaches the value stored
under this key.
Key Name Key
Number
Type Default Setting
PSKEY_PAGETABLE_DESTRUCTION_DELAY 0x0239 TIME 50*MILLISECOND
The default delay in microseconds from the point at which a buffer is redirected until its page table and any
mmu memory allocated to it can be freed.
Buffers used to receive data from the host are redirected to point to a dummy buffer when a connection is
torn down. This enables reception to continue on this buffer (connection) handle for a certain period after a