MMA5206WR2 datasheet(49/61 Pages) FREESCALE

49 / 61 page

Sensors

Freescale Semiconductor

MMA52xxWR

Preliminary

PROGRAMMING MODE VIA PSI5

5.1

Introduction

Programming mode via PSI5 is a synchronous communication mode that allows for bidirectional communication with the de-

vice. Programming mode is intended for factory programming of the OTP array. It is not intended for use in normal operation.

5.2

Programming Mode Via PSI5 Entry

The device enters programming mode if and only if the following sequence occurs:

• The device is unlocked (the LOCK_U bit in the DEVCFG2 register is ‘0’).

• At least 31 sync pulses are detected, directly preceding the Programming Mode Entry Short Command during the

Programming Mode Entry Window shown in Figure 32.

– The window timing is defined in Section 2.6 (tPME).

– The Sync pulses and Programming Mode Entry command must be received with a sync pulse period

of tS-S_PM_L

If the Programming Mode entry requirement is not met:

• Programming Mode Entry is blocked until the device is Reset.

• The device proceeds with PSI5 Initialization Phase 2, and PSI5 Initialization Phase 3.

• The device enters normal mode, and responds as programmed to normal sync pulses.

If the Programming Mode entry requirement is met:

• Normal transmissions to sync pulses are terminated.

• After a pre-defined Start Delay, the device begins to decode PSI5 Short and Long Commands.

• The device responds only to valid PSI5 Short and Long Commands addressed to Sensor Address ‘001’, as

defined in Table 18.

Note: The sync pulse pull-down is disabled in the Programming Mode Entry Window regardless of the state of the SYNCPD bit.

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