HC705E5GRSSLASHD datasheet(74/148 Pages) NXP

No. de pieza	HC705E5GRS/D

Descripción Electrónicos	General Release Specification

PDF	148 Pages

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Fabricante Electrónico	NXP [NXP Semiconductors]

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Motorola Bus (M Bus) Interface

General Release Specification

MC68HC705E5 — Rev. 1.0

Motorola Bus (M Bus) Interface

11.5.1 Start Signal

When the bus is free (for example, no master device is engaging the bus

and both SCL and SDA lines are at logical high), a master may initiate

communication by sending a start signal. As shown in Figure 11-1, a

start signal is defined as a high-to-low transition of SDA while SCL is

high. This signal denotes the beginning of new data transfer (each data

transfer may contain several bytes of data) and wakes up all slaves.

Figure 11-1. M-Bus Transmission Signal Diagram

101

NO ACKNOWLEDGE

MSB

LSB

SDA

SCL

START SIGNAL

STOP SIGNAL

LSB

ACKNOWLEDGE BIT

101

NO ACKNOWLEDGE

MSB

LSB

SDA

SCL

START SIGNAL

STOP SIGNAL

LSB

ACKNOWLEDGE BIT

REPEATED START SIGNAL

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC705E5GRS/D Datasheet(PDF) 74 Page - NXP Semiconductors