TOIM5232

www.vishay.com

Vishay Semiconductors

Rev. 1.3, 04-Jul-12

4

Document Number: 81749

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

X: do not care



S1, S2: user programmable bit to program the outputs S1

and S2



S0: IrDA pulse select



S0 = (1): 1.627 μs output pulses



S0 = (0): 3/16 bit time pulses, not recommended



B0 to B3: baud rate select words according following table.

Example:



To set TOIM5232 at COM2 port (2F8) to 9600 bit/s with

3/16 bit time pulse duration send to the TOIM5232 in

programming mode in e.g. “basic”



OUT &H2F8, (&H6)



For same port, 9600 bit/s and 1.627 μs pulse duration send



OUT &H2F8, (&H16)



For additionally activating S1 send



OUT &H2F8, (&H36)

Note

IrDA standard only supports 2.4 kbit/s, 9.6 kbit/s, 19.2 kbit/s,

57.6 kbit/s, and 115.2 kbit/s (3.6864 MHz clock). Doubling the baud

rates is allowed by doubling the clock frequency.

SOFTWARE FOR THE TOIM4232 AND TOIM5232 UART PROGRAMMING

For proper operation, the RS232 must be programmed (using 8 bit, 1 stop, no parity) to send a two character control word, YZ.

The control word YZ is composed of two characters, written in hexadecimal, in format: YZ. The transfer rate for programming

must be identical with the formerly programmed data rate, or after resetting the TOIM5232, the default rate of 9600 bit/s is used.

Note

• It is recommended reading the I/O buffer after transmission waiting the specified latency allowance. That avoids receiving unexpected data

from pulses stochastically generated by many transceivers during the latency time.

CONTROL BYTE (8 BIT)

FIRST CHARACTER

SECOND CHARACTER

X

S2

S1

S0

B3B2B1B0

LSB

BAUD RATE SELECT WORDS

B3

B2

B1

B0

CHAR

BAUD RATE

0000

0

115.2 kHz

0001

1

57.6 kHz

0010

2

38.4 kHz

0011

3

19.2 kHz

0100

4

14.4 kHz

0101

5

12.8 kHz

0110

6

9.6 kHz

0111

7

7.2 kHz

1000

8

4.8 kHz

1001

9

3.6 kHz

1010

A

2.4 kHz

1011

B

1.8 kHz

1100

C

1.2 kHz

STEP.

RESET

BR/D

TD_UART

RD_UART

RD_IR

TD_IR

DESCRIPTION AND COMMENTS

1High

X

X

X

X

X

Resets all internal registers. Resets to

IrDA default data rate of 9600 bit/s

2Low

X

X

X

X

X

Wait at least 2 ms, to allow start-up of

internal clock. When external clock is

used: wait at least 7 μs.

3Low

High

X

X

X

X

Wait at least 7 μs. TOIM5232 now is set to

the control word programming mode

4Low

High

YZ

with Y = 1:

1.627 μs

Y = 0

3/16 bit length

XX

X

Sending the control word YZ.

Examples: Send “1Z” if 1.627 μs pulses

are intended to be used. Otherwise send

“0Z” for 3/16 bit period pulses. “Y6”

keeps the 9.6 kbit/s data rate. Z = 0 sets

to 115.2 kbit/s, see programming table.

Wait at least 1 μs for hold-time.

5

Low

Low

Data

Data

Data

Data

With BR/D = 0, TOIM5232 is in the data

communication mode. Both RESET and

BR/D must be kept low (“0”) during data

transmission. Reprogramming to a new

data rate can be resumed by restarting

from step 3. The UART itself also must set