u3742bm ATMEL Corporation, u3742bm Datasheet - Page 23

• Manufacturer Part Number: u3742bm
• Description: Uhf Ask/fsk Receiver
• Manufacturer: ATMEL Corporation

Figure 24. Timing of the Register Programming
Programming the
Configuration Register
4735A–RKE–11/03
DATA (U3742BM)
Serial bi-directional
data line
Out1
(microcontroller)
Receiving
mode
X
X
t
1
The configuration registers are programmed serially via the bi-directional data line
according to Figure 24 and Figure 25.
Figure 25. One-wire Connection to a Microcontroller
To start programming, the serial data line DATA is pulled to 'L' for the time period t
the microcontroller. When DATA has been released, the receiver becomes the master
device. When the programming delay period t
chronization pulses with the pulse length t
window occurs. The delay until the program window starts is determined by t
tion is defined by t
microcontroller pulls down pin DATA for the time period t
no programming pulse t
grammed in this way. The time frame to program a bit is defined by t
Bit 14 is followed by the equivalent time window t
acknowledge pulse t
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. The register must be pro-
grammed twice in that case.
Programming of a register is possible both during sleep and active mode of the receiver.
t
2
(U3742BM)
t
Data
3
U3742BM
(Startbit)
t
Bit 1
("0")
4
Internal pull-up
t
t
t
6
7
5
resistor
5
. Within the programming window, the individual bits are set. If the
8
(E_Ack) occurs if the just programmed mode word is equivalent to
7
(Register-
select)
Bit 2
("1")
is issued, this bit is set to '1'. All 14 bits are subsequently pro-
Programming frame
DATA
Bi-directional
data line
3
. After each of these pulses, a programming
Bit 13
("0")
(Poll8)
I/O
2
has elapsed, it emits 14 subsequent syn-
9
. During this window, the equivalent
Microcontroller
(Poll8R)
Bit 14
("1")
7
during t
Out 1 (microcontroller)
t
8
5
t
9
, the bit is set to '0'. If
6
T
U3742BM
.
Sleep
Startup
mode
4
, the dura-
1
23
by