User's Manual

Datalogic Scanning, Inc
959 Terry Street
Eugene, Oregon 97402
Page 57 10/23/2009
Revision X2
Most systems do not require the BlueCore to emit a wakeup signal to wake up the peer device. Systems
using the BCSP transport, for example, support the host and baseband entering a deep sleep state, in which
their UARTs are disabled. The devices may enter deep sleep when they choose, without warning that they
are about to enter deep sleep and without signaling when they are in deep sleep. When one device wishes to
send data to its peer it sends a message; the message can be lost (because the peer's UART may be turned
off) but the presence of the message rouses the peer. For reliable BCSP channels the message is resent if it
has not been acknowledged after a delay (set by PSKEY_UART_ACK_TIMEOUT
), and the message
normally gets through the second time, as the peer is then awake. This mechanism is entirely adequate for
most systems, but using a host wakeup signal may reduce delay implied by
PSKEY_UART_ACK_TIMEOUT
.
This use of wakeup signals by the BlueCore is turned off by default, as this suits most systems.
This PS key has four uint16 parameters:
Enable: Values: 1 => enable mechanism
4 => disable mechanism
Sleep_Delay: Milliseconds after tx to host or rx from host, after
which host will be assumed to have gone into its
deep sleep state. (Range 1 -> 65535.)
When using BCSP or H5 host transports it is
recommended that this is greater than the
acknowledge delay (set by PSKEY_UART_ACK_TIMEOUT
).
Break_Length: Duration of wake signal in milliseconds.
(Range 1 -> 1000.)
Pause_Length: Milliseconds between end of wake signal and
sending data to the host. (Range 0 -> 1000.)
Key Name Key Number Type Default Setting
PSKEY_HOSTIO_THROTTLE_TIMEOUT 0x01c8 TIME 200 * MILLISECOND
This key modifies the behaviour of the BlueCore's host interface code. It should only be configured on
advice from CSR.
PSKEY_NOTE_START If the scheduler is blocked by interrupts (for a time specified by
PSKEY_SCHED_THROTTLE_TIMEOUT
), execution of the hostio interrupt handlers is delayed to give
the scheduler time to run. The maximum time for which these interrupt handlers can be delayed is specified
by this PS key (in microseconds). PSKEY_NOTE_END
Key Name Key Number Type Default Setting
PSKEY_PCM_ALWAYS_ENABLE 0x01c9 bool FALSE
By default, the PCM port is only enabled when it is in use for audio. If this key is set to TRUE, the PCM
port will be turned on when the chip boots and will remain on until reset. This has considerable
implications for power consumption.
(Type bool is fundamentally a uint16 with values 0 and 1 mapping to FALSE and TRUE.)
Key Name Key Number Type Default Setting
PSKEY_UART_HOST_WAKE_SIGNAL 0x01ca uint16 0x0000
BlueCore can be configured to output a wakeup signal to the host prior to sending it data if it considers that