CYW20702
When running in SPI mode, the CYW20702 has a mode where it enters Sleep mode when there is no activity on the SPI interface for
a specified (programmable) amount of time. Idle mode is detected when the SPI_CSN is left deasserted. Whether to sleep on an idle
interface and the amount of time to wait before entering Sleep mode can be programed by the host. Once the CYW20702 enters
sleep, the host can wake it by asserting SPI_CSN. If the host decides to sleep, the CYW20702 will wake up the host by asserting
SPI_INT when it has data for it.
Note: Successful operation of the power management handshaking signals requires coordinated support between the device
firmware and the host software.
Table 2. Power Control Pin Summary
Pin
Direction
Description
BT_WAKE
(GPIO_0)
Host output
BT input
Bluetooth device wake-up: Signal from the host to the Bluetooth device that the host requires
attention.
■ Asserted = Bluetooth device must wake up or remain awake.
■ Deasserted = Bluetooth device may sleep when sleep criteria are met.
The polarity of this signal is software configurable and can be asserted high or low. By default,
BT_WAKE is active-low (if BT-WAKE is low it requires the device to wake up or remain awake).
For USB applications, this can be used for setting Airport mode (radio disable mode).
HOST_WAKE
(GPIO_1)
BT output
Host input
Host wake-up. Signal from the Bluetooth device to the host indicating that Bluetooth device
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
(GPIO_5)
BT output
BT input
Clock request
■ Asserted = External clock reference required
■ Deasserted = External clock reference may be powered down
For the CYW20702A1KWFBG, the polarity of CLK_REQ is active low.
REG_EN
Enables the internal preregulator and main regulator outputs. REG_EN is active-high.
■ 1 = Enabled
■ 0 = Disabled
3.6.3 BBC Power Management
The device provides the following low-power operations for the BBC:
■ Physical layer packet handling turns RF on and off dynamically within packet TX and RX.
■ Bluetooth specified low-power connection mode (Sniff). While in this low-power connection mode, the device runs on the Low
Power Oscillator and wakes up after a predefined time period.
Document Number: 002-14773 Rev. *L
Page 12 of 55
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