MC33593

MOTOROLA SEMICONDUCTORS PRODUCTS

15

revision 7.0, 5 February 2002

© Motorola, Inc., 2002.

STATE MACHINE WITH STROBE PIN CONTROL

Figure 16 details the state machine when the strobe oscillator is disabled (SOE=0).

Figure 16: State machine with STROBE pin control

State 6:

Programming SOE=0 sets ROMEO2 to state 6. The circuit is in Sleep mode.

State 7:

A high level applied on STROBE sets the circuit into state 7. If an ID or its complement is detected, the state

machine advances to state 8. If not, it will stay in state 7 as long as STROBE is high.

State 8:

After ID or its complement detection, ID byte is sent to the microcontroller on MOSI line at 310kBd. This warns

the microcontroller that data are received which means that an high level has to be maintained on STROBE. At

any time a low level applied on STROBE sets the circuit into state 6.

State 7

Run mode

Waiting for ID word

State 8

Run mode

Send an ID word

ID detected

State 10

Run mode

Output data & clock

State 6

Sleep mode

STROBE=0

STROBE=0

STROBE=0

STROBE=1

SPI master

State 9

Run mode

Waiting for Header

HE=1

HE=0

Header received

STROBE=0

State 11

Run mode

Output data

EOM received

STROBE=0

Freescale Semiconductor, Inc.

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