PRELIMINARY
CYW20713
3.4 Link Control Layer
The link control layer is part of the Bluetooth link control functions implemented in dedicated logic in the link control unit (LCU). This
layer consists of the Command Controller that takes commands from the software and other controllers that are activated or configured
by the Command Controller to perform the link control tasks.
There are two major states–standby and connection. Each task establishes a different state in the Bluetooth link controller. In addition,
there are eight substates—page, page scan, inquiry, inquiry scan, park, sniff subrate, and hold.
3.5 Test Mode Support
The CYW20713 fully supports Bluetooth Test Mode, including the transmitter tests, normal and delayed Loopback tests, and the
reduced hopping sequence.
In addition to the standard Bluetooth Test mode, the device supports enhanced testing features to simplify RF debugging and quali-
fication and type approval testing.
These test features include:
■ Fixed frequency carrier wave (unmodulated) transmission
❐ Simplifies some type approval measurements (Japan)
❐ Aids in transmitter performance analysis
■ Fixed frequency constant receiver mode
❐ Directs receiver output to I/O pin
❐ Allows for direct BER measurements using standard RF test equipment
❐ Facilitates spurious emissions testing for receive mode
■ Fixed frequency constant bit stream transmission
❐ Unmodulated, 8-bit fixed pattern, PRBS-9, or PRBS-15
❐ Enables modulated signal measurements with standard RF test equipment
■ Packetized connectionless transmitter test
❐ Hopping or fixed frequency
❐ Multiple packet types supported
❐ Multiple data patterns supported
■ Packetized connectionless receiver test
❐ Fixed frequency
❐ Multiple packet types supported
❐ Multiple data patterns supported
3.6 Power Management Unit
The Power Management Unit (PMU) provides power management features that can be invoked through power management registers
or packet handling in the baseband core. This section contains descriptions of the PMU features.
3.6.1 RF Power Management
The BBC generates power-down control signals for the transmit path, receive path, PLL, and power amplifier to the 2.4 GHz trans-
ceiver. The transceiver then processes the power-down functions, accordingly.
3.6.2 Host Controller Power Management
The host can place the device in a sleep state, in which all nonessential blocks are powered off and all nonessential clocks are
disabled. Power to the digital core is maintained so that the state of the registers and RAM is not lost. In addition, the LPO clock is
applied to the internal sleep controller so that the chip can wake automatically at a specified time or based on signaling from the host.
The goal is to limit the current consumption to a minimum, while maintaining the ability to wake up and resume a connection with
minimal latency.
If a scan or sniff session is enabled while the device is in Sleep mode, the device automatically will wake up for the scan/sniff event,
then go back to sleep when the event is done. In this case, the device uses its internal LPO-based timers to trigger the periodic wake
up. While in Sleep mode, the transports are idle. However, the host can signal the device to wake up at any time. If signaled to wake
up while a scan or sniff session is in progress, the session continues but the device will not sleep between scan/sniff events. Once
Sleep mode is enabled, the wake signaling mechanism can also be thought of as a sleep signaling mechanism, since removing the
wake status will often cause the device to sleep.
In addition to a Bluetooth device wake signaling mechanism, there is a host wake signaling mechanism. This feature provides a way
for the Bluetooth device to wake up a host that is in a reduced power state.
Document Number: 002-14806 Rev. *C
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