ST7-EPB

1 Getting Started

UM0028 Rev 4

9/15

Note:

When using the ST7MDTS1-EPB, the VDD_APPLI is not connected to the ST7. When

setting up your application for in-circuit programming, refer to the ICP Interface diagram in

the In-CIrcuit Programming section of the ST7SCR Datasheet, instead of the diagram

provided above.

Using the ICC protocol for in-circuit programming requires that a minimum of 4 and as many

as 6 pins of your ST7 be connected to your programming board (see

Table 1). Additional

notes about these connections are provided in this section.

Note:

For specific ICC connection requirements for microcontroller introduced after the publication

of this document, please refer to the microcontroller datasheet.

Isolation of ICCDATA and ICCCLK pins

From the moment that your ST7-EPB is plugged into the application board, the ICCDATA

and ICCCLK pins must not be used by other application devices, even when you are not

programming the ST7. If the application uses these pins as inputs, isolation such as a serial

resistor must be implemented to prevent other application devices from forcing a signal on

either of these pins. The application board must not drive current in excess of 1mA.

If the ICCDATA and ICCCLK pins are only used as outputs by the application, no signal

isolation is necessary.

For ST7 without an ICCSEL pin, during normal operation the ICCCLK pin must be pulled-up

internally or externally (10K

Ω pull-up required in noisy environments). This is to avoid

entering ICC mode unintentionally during a reset.

Isolation of the RESET pin

During an ICC session, your ST7-EPB must control the ST7’s RESET pin. No external reset

can be generated by the application. This can lead to a conflict if the application reset

circuitry signal exceeds 5mA (push-pull output or pull-up resistor <1k). To avoid such

conflicts, a Shottky diode can be used to isolate the application reset circuit.

ICCSEL/VPP pin

The application pull-down resistor must not be lower than 10k

Ω.

Table 1.

ICC connection requirements

ST7 pin

Connects to...

ICCDATA

ICC input serial data pin

ICCDATA

ICCCLK

ICC output serial clock pin

ICCCLK

RESET

Device reset

ICCRESET

ICCSEL/VPP

Programming voltage

ICCSEL/VPP

Main clock input for external

ICCOSC

VDD

Device power supply

VDD_APPLI

VSS

Device power supply (ground)

GND

#

Optional connection for ST7MDTxx-EPB, see text.