STA2500DTR STMICROELECTRONICS [STMicroelectronics], STA2500DTR Datasheet - Page 35

• Manufacturer Part Number: STA2500DTR
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

STA2500D
Figure 10. Deep sleep mode entry and wake-up through H4 SPI
Deep sleep mode entry and wake-up through H4 UART or H4 SPI with
handshake
This method is supported by both H4 UART and H4 SPI. The description below is for H4
UART.
It requires BT_CLK_REQ_OUT_1, BT_WAKEUP and BT_HOST_WAKEUP. The
BT_WAKEUP is used as wake-up signal from the Host, the BT_CLK_REQ_OUT_1 requires
the clock from the Host and BT_HOST_WAKEUP is used as a wake-up signal from the
Bluetooth Controller.
●
●
1.
Deep sleep mode entry
The Host tells the STA2500D that it can go in Deep Sleep mode by forcing the
BT_WAKEUP of the STA2500D to ‘0’. The STA2500D decides to go in Deep Sleep
mode, or not, depending on its scheduled activity and on the number of events or data
packets to be sent to the Host. In case it decides to go in Deep Sleep mode, it asserts
BT_CLK_REQ_OUT_1 low to tell the Host that it does not need the clock anymore. On
the contrary, if it still wants the interface active for up-transmission, it keeps
BT_HOST_WAKEUP to ‘1’ as long as needed before de-asserting
BT_CLK_REQ_OUT_1. This is illustrated in
Deep sleep mode wake-up
The wake-up procedure can be initiated by the Host or by the STA2500D. In the latter
case, it can be with or without communication, depending if there are data to be
transmitted to the Host.
Wake-up initiated by the Host
The Host sets the BT_WAKEUP pin of the STA2500D to ‘1’. Then the STA2500D asks
the Host to restart the system clock by setting BT_CLK_REQ_OUT_1 to ‘1’. When the
clock is available and stable, the STA2500D puts BT_UART_RTS low to allow
communication. In case the STA2500D wants to send events to the Host, it then puts
SPI on
SPI on
HOST_WAKEUP =‘ 1’ or ‘ 0’
HOST_WAKEUP =‘ 1’ or ‘ 0’
Active
Active
Sleep Mode
BB
BB
Sleep Mode
Doc ID 16067 Rev 1
BT Controller: BT_SPI_INT =‘ 1 ’
Host:
Host:
OR
OR
BT Controller:SPI_INT=‘ 1’
BT_WAKEUP=‘1’
BT_WAKEUP=‘1’
Host:
Host:
Host:
AND
BT Controller:BT_CLK_ REQ_OUT_1=‘ A’
Host:
AND
BT Controller: CLK_REQ_OUT_1 =‘ A ’
BT_WAKEUP=‘0’
BT_WAKEUP=‘0’
Figure
BT_WAKEUP=‘1’
BT_WAKEUP=‘1’
11.
SPI off
SPI off
CLK_REQ_OUT_1 = ‘ A’ :
CLK_REQ_OUT_1 = ‘ A’ :
Active
Active
Deep Sleep
General specification
‘ P’ :
‘ P’ :
Mode
Mode
Sleep Mode
BB
BB
Sleep Mode
Active
Active
Passive
Passive
HOST_WAKEUP =‘ 0’
HOST_WAKEUP =‘ 0’
high/low
high/low
SPI off
SPI off
low/high
low/high
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