ATA5823 ATMEL Corporation, ATA5823 Datasheet - Page 52

• Manufacturer Part Number: ATA5823
• Description: Uhf Ask/fsk Transceiver Ata5823 Ata5824
• Manufacturer: ATMEL Corporation

14. Operation Modes
14.1
14.1.1
52
RX Operation
ATA5823/ATA5824
RX Polling Mode
The transceiver is set to RX operation with the bits OPM0, OPM1 and OPM2 in control register 1
Table 14-1.
The transceiver is designed to consume less than 1 mA in RX operation while being sensitive to
signals from a corresponding transmitter. This is achieved via the polling circuit. This circuits
enable the signal path periodically for a short time. During this time the Bit-check logic verifies
the presence of a valid transmitter signal. Only if a valid signal is detected the transceiver
remains active and transfers the data to the connected microcontroller. This transfer take place
either via the TX/RX data buffer or via the pin SDO_TMDO. If there is no valid signal present the
transceiver is in sleep mode most of the time resulting in low current consumption. This condition
is called RX polling mode. A connected microcontroller can be disabled during this time.
All relevant parameters of the polling logic can be configured by the connected microcontroller.
This flexibility enables the user to meet the specifications in terms of current consumption, sys-
tem response time, data rate etc.
In RX mode the RF transceiver is enabled permanently and the Bit-check logic verifies the pres-
ence of a valid transmitter signal. If a valid signal is detected the transceiver transfers the data to
the connected microcontroller. This transfer takes place either via the TX/RX data buffer or via
the pin SDO_TMDO.
If the transceiver is in RX polling mode, it stays in a continuous cycle of three different modes. In
sleep mode, the RF transceiver is disabled for the time period T
rent of I
circuits are enabled and settled. In the following Bit-check mode, the incoming data stream is
analyzed bit by bit versus a valid transmitter signal. If no valid signal is present, the transceiver is
set back to sleep mode after the period T
tistical process. An average value for T
T
consumption is I
RX_ACTIVE (see
ferent in battery application or car application. To calculate I
VS1,2 in battery application or VS2 in car application (see section
General” on page
I
Poll
Startup_PLL
OPM2
=
I
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
0
0
IDLE_X
S
= I
the current consumption is I
IDLE_X
Control Register 1
T
Sleep
. During the start-up period, T
S
Figure
72).
OPM1
= I
+
1
1
T
Startup_Sig_Proc_X
I
Startup_PLL_X
Sleep
14-1). The average current consumption in RX polling mode I
+
T
Startup_PLL
OPM0
0
1
T
Startup_PLL
. The condition of the transceiver is indicated on pin
S
Bit-check
+
Bit-check
= I
T
Startup_Sig_Proc
RX_X
Startup_PLL
+
. This period varies check by check as it is a sta-
is given in the electrical characteristics. During
. During T
I
RX_X
and T
+
T
Startup_Sig_Proc
T
Startup_Sig_Proc
Bitcheck
Poll
Startup_Sig_Proc
RX polling mode
the index X must be replaced by
Sleep
RX mode
Function
“Electrical Characteristics:
while consuming low cur-
+
and T
T
, all signal processing
Bitcheck
Bit-check
4829D–RKE–06/06
the current
Poll
is dif-