MMA5206WR2 datasheet(32/61 Pages) FREESCALE

32 / 61 page

Sensors

Freescale Semiconductor

MMA52xxWR

Preliminary

PSI5 LAYER AND PROTOCOL

4.1

Communication Interface Overview

The communication interface between a master device and the Opuntia is established via a PSI5 compatible 2-wire interface,

with parallel or serial (daisy-chain) connections to the satellite modules. Figure 25 shows one possible system configuration for

multiple satellite modules in parallel.

Figure 25. PSI5 Satellite Interface Diagram

4.2

Data Transmission Physical Layer

The device uses a two wire interface for both its power supply (VCC), and data transmission. The PSI5 master supplies a pre-

regulated voltage. Data transmissions and synchronization control from the PSI5 master to the device are accomplished via mod-

ulation of the supply voltage. Data transmissions from the device to the PSI5 master are accomplished via modulation of the cur-

rent on the power supply line.

4.2.1

Synchronization Pulse

The PSI5 master modulates the supply voltage in the positive direction to provide synchronization of the satellite sensor data.

Upon reception of a synchronization pulse, the device delays a specified period of time, called a time slot, before transmitting

acceleration data. For more details regarding time slots, refer to Section 3.1.4, and Section 4.5.

Figure 26. Synchronous Communication Overview

MMA52xx

VCC

IData

SATELLITE MODULE #1

VCC

VSS

VCC_OUT

VSS_OUT

MASTER DEVICE

SATELLITE MODULE #2

VCC

VSS

VCC_OUT

VSS_OUT

Discrete

Components

Discrete

Components

VSS

VCC

IData

VSS

MMA52xx

GND

VIDLE

SYNC PULSES

VIDLE+ ΔVSYNC

IIDLE

IIDLE + IMOD

MMA5206WR2 数据表(PDF) 32 Page - Freescale Semiconductor, Inc

MMA5206WR2 数据表(HTML) 32 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61

数据表下载