STA2500DTR STMICROELECTRONICS [STMicroelectronics], STA2500DTR Datasheet - Page 32

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

General specification
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Figure 6.
Deep sleep mode entry and wake-up through enhanced H4 SPI
In this case no additional signals are needed to control the Deep Sleep mode and the wake-
up mechanism except for BT_CLK_REQ_OUT_x (BT_CLK_REQ_OUT_1 for active high
polarity and BT_ CLK_REQ_OUT_2 for active low polarity).
The enhanced H4 protocol makes use of three messages: SLEEP, WAKEUP and WOKEN.
More details on the enhanced H4 protocol can be found in
●
●
1.
UART on
UART on
HOST_WAKEUP =‘ 1’ or ‘ 0’
HOST_WAKEUP =‘ 1’ or ‘ 0’
Deep sleep mode entry
Entering Deep Sleep mode can only be initiated by the Host sending a SLEEP
message to the Bluetooth Controller.
If that one accepts it, the device enters Deep Sleep mode: consequently the Bluetooth
Controller de-asserts BT_CLK_REQ_OUT_x and internally gates the system clock.
This is illustrated in
If there is still pending activity at the Bluetooth side on the air, the Bluetooth Controller
does not immediately enter Deep Sleep mode and therefore BT_CLK_REQ_OUT_x
stays 'active' during this period: however the Bluetooth Controller will go in Deep Sleep
mode at the end of the air activity.
If there is pending data to be transferred to the Host, the Bluetooth Controller will
request a data transfer: however the Bluetooth Controller will go in Deep Sleep mode at
the end of the data transfer.
Deep sleep mode wake-up
Wake-up can be requested by the Host or autonomously by the Bluetooth Controller. In
the latter case, it can be with or without communication on the interface (i.e. during
Page scan, there is no data to transfer to the Host).
Wake-up initiated by the Host
In the case of a wake-up by the Host, it sends a WAKEUP command and waits for a
WOKEN response before starting the data exchange. Of course the Bluetooth
Controller must first request the system clock through BT_CLK_REQ_OUT_x.
It should be noted that the WAKEUP message is decoded in the Bluetooth Controller's
Active
Active
Deep sleep mode entry and wake-up through H4 UART
Sleep Mode
BB
BB
Sleep Mode
Figure
Host:
BT Controller:BT_UA RT_RTS = ‘0’
Host:
BT Controller: UART_ RTS= ‘0’
Doc ID 16067 Rev 1
7.
BT_UA RT_RXD=‘ 1’
BT_HOST_WAKEUP= ‘ 1’
Or
Or
UART_ RXD=‘ 1’
HOST_WAKEUP= ‘1’
BT Controller: BT_UA RT_RTS= ‘ 1’
Host:
Host:
BT Controller: UART_ RTS= ‘ 1’
BT Controller: BT_CLK_ REQ_OUT_1 =‘ A’
Host:
Host:
AND
AND
BT Controller: CLK_REQ_OUT_1 =‘ A’
BT_UA RT_RXD =‘ 0’
BT_UA RT_RTS= ‘ 0’
BT_UA RT_RXD=‘ 1’
UART_ RXD=‘ 0’
and
and
UART_ RXD=‘ 1’
UART_ RTS= ‘ 0’
BT_CLK_REQ_OUT_1 =
UART off
UART off
Section
Active
Active
8.2.
Deep Sleep
‘ P’ :
‘A’ :
Mode
Sleep Mode
BB
BB
Sleep Mode
Active
Passive
HOST_WAKEUP =‘ 0’
HOST_WAKEUP =‘ 0’
STA2500D
high/low
low/high
UART off
UART off