T5743P3 ATMEL [ATMEL Corporation], T5743P3 Datasheet - Page 11

• Manufacturer Part Number: T5743P3
• Description: UHF ASK/FSK Receiver
• Manufacturer: ATMEL [ATMEL Corporation]

Sleep Mode
4569A–RKE–12/02
During T
tee the reception of a transmitted command the transmitter must start the telegram with
an adequate preburst. The required length of the preburst depends on the polling
parameters T
(T
to be tested.
The following formula indicates how to calculate the preburst length.
T
The length of period T
the extension factor XSleep (according to Table 9), and the basic clock cycle T
calculated to be:
T
In US- and European applications, the maximum value of T
is set to 1. The time resolution is about 2 ms in that case. The sleep time can be
extended to almost half a second by setting XSleep to 8. XSleep can be set to 8 by bit
XSleep
According to Table 8, the highest register value of sleep sets the receiver into a perma-
nent sleep condition. The receiver remains in that condition until another value for Sleep
is programmed into the OPMODE register. This function is desirable where several
devices share a single data line and may also be used for microcontroller polling — via
Pin POLLING/_ON, the receiver can be switched on and off.
I
Spoll
Preburst
Sleep
Start,µC
=
= Sleep ´ X
Std
). Thus, T
³ T
I
------------------------------------------------------------------------------------------------------------- -
Sleep
Soff
to 1.
Sleep
´
and T
Sleep
T
T
+ T
Sleep
Sleep
, T
Bit-check
Sleep
Startup
Startup
Startup
+
+
Sleep
´ 1024 ´ T
I
Son
T
depends on the actual bit rate and the number of bits (N
+ T
the receiver is not sensitive to a transmitter signal. To guaran-
, T
Startup
is defined by the 5-bit word Sleep of the OPMODE register,
´
Bit-check
Bit-check
(
T
Startup
+
Clk
T
and the start-up time of a connected microcontroller
Bit-check
+ T
+
Start_µC
T
Bit-check
)
Sleep
is about 60 ms if XSleep
T5743
Bit-check
Clk
. It is
11
)