SC18IS600_601_3

© NXP B.V. 2006. All rights reserved.

Product data sheet

Rev. 03 — 13 December 2006

9 of 28

NXP Semiconductors

SC18IS600/601

formula:

The least significant bit of I2CTO (TE bit) is used as a time-out enable/disable. A logic 1

will enable the time-out function.

On the SC18IS600 the time-out oscillator operates at 57.6 kHz. For the SC18IS601 the

time-out oscillator frequency can be determined using the following formula:

This oscillator is fed into a 16-bit down counter. The down counter’s lower nine bits are

loaded with ‘1’, while the upper seven bits are loaded with the contents of I2CTO.

The time-out value is an approximate value.

In the case of arbitration loss, the SC18IS600/601 will transmit a START condition when

the bus becomes free unless the time-out condition is reached. If the time-out condition is

be read in I2CStat.

Table 6.

I2CClk (decimal)

5 (minimum)

369 kHz

7

263 kHz

9

204 kHz

19

97 kHz

255 (maximum)

7.2 kHz

I

2

C-bus clock frequency

CLKIN

4

I 2CClk

×

---------------------------- Hz

()

=

Table 7.

Bit

Symbol

Description

7:1

TO[7:1]

Time-out value

0

TE

Enable/disable time-out function

logic 0 = disable

logic 1 = enable

Fig 9.

Time-out value

Time-out oscillator frequency

CLKIN

128

------------------- Hz

()

=

57.6 kHz

OSCILLATOR

002aab715

16-BIT DOWN COUNTER

[I2CTO][111111111]

time-out