U3741BM Datasheet, PDF (21/32 Pages) ATMEL Corporation – UHF ASK RECEIVER IC

U3741BM
• f_RM is lower than the lowest feasible frequency of a data signal. By this means, RM
cannot be misinterpreted by the connected microcontroller.
• If the receiver is set back to polling mode via pin DATA, RM cannot be canceled by
accident if t1 is applied according to the proposal in the section “Programming the
Configuration Register” on page 21.
By means of that mechanism, the receiver cannot lose its register information without
communicating that condition via the reset marker RM.
Figure 19. Generation of the Power-on Reset
V_S
POR
t_Rst
DATA (U3741BM)
X
V_ThReset
Figure 20. Timing of the Register Programming
Out1
(microcontroller)
t1
t2
t3
t5
t4
t6
t7
DATA (U3741BM)
X
1/f_RM
t9
T_Sleep
t8
X
Serial bi-directional
X
data line
Receiver
on
Programming the
Configuration Register
Bit 1
("0")
(Start bit)
Bit 2
("1")
(Register select)
Programming Frame
Bit 13
("0")
(Poll8)
Bit 14
("1")
(Poll8R)
X
Startup
mode
The configuration registers are programmed serially via the bi-directional data line
according to Figure 20 and Figure 21.
Figure 21. One-wire Connection to a Microcontroller
U3741BM
Internal pull-up
resistor
Bi-directional
data line
DATA
I/O
microcontroller
DATA (U3741BM)
Out 1 (µC)
21
4662B–RKE–10/04