ATA5423 ATMEL Corporation, ATA5423 Datasheet - Page 52

• Manufacturer Part Number: ATA5423
• Manufacturer: ATMEL Corporation

9. Operation Modes
9.1
9.1.1
52
RX Operation
ATA5423/25/28/29 [Preliminary]
RX Polling Mode
The transceiver is set to RX operation with the bits OPM0 and OPM1 in control register 1.
Table 9-1.
The transceiver is designed to consume less than 1 mA in RX operation while remaining sensi-
tive to signals from a corresponding transmitter. This is achieved via the polling circuit. This
circuit enables 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 does the
transceiver remain active and transfer the data to the connected microcontroller. This transfer
takes place either via the TX/RX data buffer or via the pin SDO_TMDO. When there is no valid
signal present, the transceiver is in sleep mode most of the time, resulting in low current con-
sumption. 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. When a valid signal is detected the transceiver transfers the
data to the connected microcontroller. This transfer take place either via the TX/RX data buffer
or via the pin SDO_TMDO.
When 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
low current of I
processing circuits are enabled and settled. In the following bit-check mode, the incoming data
stream is analyzed bit by bit to see if it is a valid transmitter signal. If no valid signal is present,
the transceiver is set back to sleep mode after the period T
check as it is a statistical process. An average value for T
teristics. During T
and T
on pin RX_ACTIVE (see
rent consumption in RX polling mode I
or base–station application. To calculate I
tery application, VS2 in 2-battery application or VS2,VAUX in base–station application (see
section
I
P
=
I
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
IDLE_X
Bit–check
“Electrical Characteristics: General” on page
OPM1
1
1
the current consumption is I
T
Control Register 1
Sleep
S
= I
Startup_PLL
+
IDLE_X
T
I
Sleep
Startup_PLL_X
Figure 9-1 on page 54
. During the start–up period, T
+
T
the current consumption is I
Startup_PLL
T
Startup_PLL
P
+
OPM0
is different in 1-battery application, 2-battery application
T
Startup_Sig_Proc
0
1
S
P
= I
the index X must be replaced by VS1,VS2 in 1-bat-
+
RX_X
I
RX_X
and
. The condition of the transceiver is indicated
66).
Figure 9-2 on page
+
T
T
Startup_PLL
Startup_Sig_Proc
S
Bit–check
Bit_check
= I
Bit–check
Startup_PLL_X
is given in the electrical charac-
and T
. This period varies check by
RX polling mode
+
T
Function
RX mode
Startup_Sig_Proc
. During T
Bitcheck
55). The average cur-
Sleep
while consuming
4841A–RKE–02/05
Startup_Sig_Proc
, all signal