BCM4354 Data Sheet
Bluetooth Power Management Unit
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 BCM4354 are:
•
•
•
•
RF Power Management
Host Controller Power Management
BBC Power Management
FM Power Management
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 transceiver. The transceiver then processes the power-down functions accordingly.
Host Controller Power Management
When running in UART mode, the BCM4354 may be configured so that dedicated signals are used for power
management hand-shaking between the BCM4354 and the host. The basic power saving functions supported
by those hand-shaking signals include the standard Bluetooth defined power savings modes and standby
modes of operation. Table 5 describes the power-control hand-shake signals used with the UART interface.
Table 5: Power Control Pin Description
Signal
Mapped to Pin
Type Description
BT_DEV_WAKE
BT_GPIO_0
I
Bluetooth device wake-up: Signal from the host to the
BCM4354 indicating that the host requires attention.
•
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.
BT_HOST_WAKE BT_GPIO_1
O
Host wake up. Signal from the BCM4354 to the host
indicating that the BCM4354 requires attention.
•
•
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.
CLK_REQ
BT_CLK_REQ_OUT O
WL_CLK_REQ_OUT
The BCM4354 asserts CLK_REQ when Bluetooth or WLAN
wants 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
BCM4354 powers up or resets when VDDIO is present.
Note: Pad function Control Register is set to 0 for these pins. See “DC Characteristics” on page 125 for more
details.
Broadcom®
October 15, 2014 • 4354-DS109-R
Page 37
BROADCOM CONFIDENTIAL
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