PRELIMINARY
CYW43438
8.3 Test Mode Support
The CYW43438 fully supports Bluetooth Test mode as described in Part I:1 of the Specification of the Bluetooth System Version 3.0.
This includes the transmitter tests, normal and delayed loopback tests, and reduced hopping sequence.
In addition to the standard Bluetooth Test Mode, the CYW43438 also supports enhanced testing features to simplify RF debugging
and qualification as well as type-approval testing. These features include:
■ Fixed f8requency carrier-wave (unmodulated) transmission
❐ Simplifies some type-approval measurements (Japan)
❐ Aids in transmitter performance analysis
■ Fixed frequency constant receiver mode
❐ Receiver output directed to an I/O pin
❐ Allows for direct BER measurements using standard RF test equipment
❐ Facilitates spurious emissions testing for receive mode
■ Fixed frequency constant transmission
❐ Eight-bit fixed pattern or PRBS-9
❐ Enables modulated signal measurements with standard RF test equipment
8.4 Bluetooth Power Management Unit
The Bluetooth Power Management Unit (PMU) provides power management features that can be invoked by either software through
power management registers or packet handling in the baseband core. The power management functions provided by the CYW43438
are:
■ RF Power Management
■ Host Controller Power Management
■ BBC Power Management
■ FM Power Management
8.4.1 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.
8.4.2 Host Controller Power Management
When running in UART mode, the CYW43438 can be configured so that dedicated signals are used for power management
handshaking between the CYW43438 and the host. The basic power saving functions supported by those handshaking signals include
the standard Bluetooth defined power savings modes and standby modes of operation.
Table 8 describes the power-control handshake signals used with the UART interface.
Table 8. Power Control Pin Description
Signal
Type
Description
Bluetooth device wake-up signal: Signal from the host to the CYW43438 indicating that the host
requires attention.
BT_DEV_WAKE
I
■ Asserted: The Bluetooth device must wake up or remain awake.
■ Deasserted: The Bluetooth device may sleep when sleep criteria are met.
The polarity of this signal is software configurable and can be asserted high or low.
Host wake-up signal. Signal from the CYW43438 to the host indicating that the CYW43438
requires attention.
BT_HOST_WAKE
CLK_REQ
O
O
■ Asserted: Host device must wake up or remain awake.
■ Deasserted: Host device may sleep when sleep criteria are met.
The polarity of this signal is software configurable and can be asserted high or low.
The CYW43438 asserts CLK_REQ when Bluetooth or WLAN directs the host to turn on the
reference clock. The CLK_REQ polarity is active-high.Add an external 100 kΩ pull-down resistor
to ensure the signal is deasserted when the CYW43438 powers up or resets when VDDIO is
present.
Note: Pad function Control Register is set to 0 for these pins.
Document Number: 002-14796 Rev. *K
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