toim3232 ETC-unknow, toim3232 Datasheet - Page 4

• Manufacturer Part Number: toim3232
• Description: Infrared Irda Integrated Interface Circuits
• Manufacturer: ETC-unknow

Application
Figure 1 shows a typical example of a UART interface.
As shown, XIN accepts the 1.8432 MHz input clock, and
B_CLK accepts the 16 times baud rate clock.
Set S1 = S0 = LOW (“0”). When RESET = 0, the
TOIM3000 sends the data to, or receives the data from the
infrared transceiver TFDS3000. If Reset is active,
RESET = 1, the TOIM3000 handles the normal electrical
data exchange with the RS232 port.
R1 = 2.2 k
line is capacitive loaded).
R2 = 100
and C2 are in parallel (V
value of R3 should be reduced, see introductory text).
Single clock operation
TOIM3000 can be operated with only a single clock. In
this case, B_CLK and XIN are tight together and con-
nected to the Baudout pin of the UART. The pulse width
is then shortened to 3/16 of the bit length and noise filter-
ing is deactivated. S1 should be connected to V
to GND.
TOIM3000/3232
UART
4 (9)
BAUDOUT
V
CC
XOUT
SOUT
Figure 1. TOIM3000 – UART interface
OUT1
SIN
W
W
, R3 = 10
optional (only necessary when RxD–RD IR
(built-in infrared port)
TD_UART
B_CLK
RESET
RD_UART
S0 S1
XIN
W
V
, C1 = 6.8
CC
TOIM3000
CC
RD_232
TD_232
= 5 V, in case of 3 V supply,
RD_IR
TD_IR
m
F and C2 = 0.1
Preliminary Information
R2
RXD
TXD
TXD
RXD
SD
R1
8 3
CC
C1, C2
and SO
TFDS
RS232
3000
m
F. C1
Figure 2 shows a typical example of an RS232 port inter-
face. The TOIM3232 interfaces the RS232 port to an
infrared transceiver. Due to the various voltage levels, an
additional level converter (discrete or integrated) is nec-
sessary. The baud rate generator is programmable. A
description of programming is given in the Chapter “Soft-
ware for the TOIM3232” page 7 (IrDA Design Guide).
When BR/D = 0, the TOIM3232 interprets RD_232 data
as data transmitted to the TFDS3000. On the other hand,
whenever BR/D = 1, the TOIM3232 interprets RD_232
as the control word. The baud rate can be programmed to
operate from 1200 bit/s to 115 kbit/s. As RS232 level
converter, EIA232 or MAX232 or equivalent should be
used.
The external resistors and capacitors needed are shown in
figure 1. Please also refer to figure 1 for the recom-
mended power supply filter and pull-up resistors.
The output pulse length can be programmed, see chapter
“Operation Description”. It is strongly recommended to
use 1.627
connector
pin 2, RXD
RS232
pin 3, TXD
pin 4, DTR
pin 7, RTS
9–pin
Figure 2. TOIM3232 – RS232 port interface
m
s output pulses to save battery power.
converter
(external infrared adapter)
Level
TELEFUNKEN Semiconductors
RESET
BR/D
TD_UART
RD_UART
X1
TOIM3232
VCC_SD
3.6842 MHz
TD_IR
RD_IR
Rev. A4, 26-Mar-96
X2
TFDS3000
VCC
TXD
RXD