ATA5743 ATMEL Corporation, ATA5743 Datasheet - Page 29

• Manufacturer Part Number: ATA5743
• Description: Ata5743 Uhf Ask/fsk Receiver
• Manufacturer: ATMEL Corporation

Figure 6-26. Data Interface
4839B–RKE–08/05
Data_out
Data_In
V
S
= 4.5 V to 5.5 V
0 V/5 V
The configuration registers are programmed serially via the bi-directional data line as demon-
strated in
To start programming, the microcontroller pulls the serial data line DATA to Low for the time
period t1. When DATA has been released, the receiver becomes the master device. When the
programming delay period t2 has elapsed, it emits 15 subsequent synchronization pulses with
the pulse length t3. After each of these pulses, a programming window occurs. The delay until
the program window starts is determined by t4, the duration is defined by t5. Within the program-
ming window, the individual bits are set. If the microcontroller pulls down pin DATA for the time
period t7 during t5, the appropriate bit is set to “0”. If no programming pulse t7 is issued, this bit
is set to “1”. All 15 bits are subsequently programmed this way. The time frame to program a bit
is defined by t6.
Bit 15 is followed by the equivalent time window t9. During this window, the equivalent acknowl-
edge pulse t8 (E_Ack) occurs if the just programmed mode word is equivalent to the mode word
that was already stored in that register. E_Ack should be used to verify that the mode word was
correctly transferred to the register; in order to do this, the register must be programmed twice.
Programming of a register is possible with the receiver in either sleep mode or in active mode.
During programming, the LNA, LO, low-pass filter IF-amplifier, and the FSK/ASK Manchester
demodulator are disabled.
The programming start pulse t1 initiates the programming of the configuration registers. If bit 1 is
set to “1”, it represents the OFF command to set the receiver back to polling mode immediately.
For the length of the programming start pulse t1, the following convention should be considered:
Similarly, programming the OFF command is initiated if the receiver is not in reset mode. If the
receiver is in reset mode, programming the OFF command is not initiated and the reset marker
(RM) is still present at pin DATA.
This period is generally used to switch the receiver to polling mode or to start the programming
of a register. In reset condition, RM can not be cancelled by accident.
Programming registers or the OFF command is initiated in any case. The registers OPMODE
and LIMIT are set to the default values. RM is cancelled if present.
• t1(min) < t1 < 5632
• t1 > 7936
Interface
Input -
Figure 6-25 on page 28
ATA5743
T
Clk
0 to 20 V
I
D
T
DATA
Clk
: t1(min) is the minimum specified value for the relevant BR_Range
and
Serial bi-directional data line
R
V
C
pup
X
L
= 5 V to 20 V
Figure
6-26.
I/O
Microcontroller
Out1 microcontroller
ATA5743
29