SC18IM700_2

© NXP B.V. 2007. All rights reserved.

Product data sheet

Rev. 02 — 10 August 2007

7 of 22

NXP Semiconductors

SC18IM700

7.1.8 Repeated START: write after write

The SC18IM700 also supports ‘write after write’ command as specified in the NXP

write command without having to issue a STOP condition between the two commands.

The host issues a write command as normal, then immediately issues a second write

command without sending a STOP (P) character after the first write command.

7.1.9 Power-down mode

The SC18IM700 can be placed in a low-power mode. In this mode the internal oscillator is

stopped and SC18IM700 will no longer respond to the host messages. Enter the

Power-down mode by sending the power-down character Z (0x5A) followed by the two

defined bytes, which are 0x5A and followed by 0xA5. If the exact message is not received,

the device will not enter the power-down state.

Upon entering the power-down state, SC18IM700 places the WAKEUP pin in a HIGH

state. To have the device leave the power-down state, the WAKEUP pin should be brought

LOW. A 1 k

Ω resistor must be connected between the WAKEUP pin and V

Fig 9.

Repeated START: read after write

002aac054

NUMBER

OF BYTES

S CHAR.

SLAVE ADR.

+ W

S CHAR.

NUMBER

OF BYTES

SLAVE ADR. + R

DATA 0

DATA N

P CHAR.

18IM responds

DATA 0

DATA N

Fig 10. Repeated START: write after write

002aac055

NUMBER

OF BYTES

S CHAR.

SLAVE ADR.

+ W

S CHAR.

NUMBER

OF BYTES

SLAVE ADR. + W

DATA 0

DATA 0

DATA N

P CHAR.

DATA N

Fig 11. Power-down mode

002aac056

Z CHAR.

0x5A

0xA5

P CHAR.