ST7SCR ICC mode entry

ST7 Flash Programming

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Appendix A

ST7SCR ICC mode entry

For an external controller to be able to put the ST7SCR into ICC mode, the procedure has to

be slightly modified because the ST7SCR has no external RESET pin to synchronize the

start of the pulse train that defines ICC mode entry. Instead the synchronization has to be

analog comparator with a threshold of 3.8V.

As shown in Figure 1, a startup delay has to be inserted, specified as follows:

Figure 1.

A.1

ROM product, ICC mode selection

this pin is high, the LVD is powered off, pin PA6 becomes a reset pin and pin PA0 becomes

To enter ICC mode:

1.

Hold the TM pin at high level.

2.

Reset the chip by applying a low level pulse on PA6

3.

Apply 38 pulses on the PA0 pin as shown in Figure 1.

4.

When the mode entry window is finished, the PA0 port acts as the ICCDATA function.

ICCCLK

38 Pulses within

ST7 internal reset phase

ICC monitor execution

Symbol

Min

Max

Unit

62.5

•ns

50 µs

+128 clk

50 µs

+384 clk

ICCDATA

3.8 V Threshold