AN2168

4 Start up configuration

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4

Start up configuration

Port 0 is used to select the start up system configuration by the mean of external pull down

resistors. During reset, Port 0 lines are set to input mode with internal pull up resistors. The port

0 pins are read at the end of the reset sequence.

The following table summarizes the port0 lines corresponding to the start up features:

Table 2.

Port 0 fields

Note: 1 A low level is applied using a pull down resistor of 8 kOhms.

For more details regarding the P0 fields and corresponding meanings, refer to ST10F27x

datasheet or user manual.

Port 0 lines

Function

Comments

P0L.0

Emulation mode

1)

P0L.1

Adapt mode

1)

P0L.4, P0L.5

Boot strap mode

1)

See Section 5: Boot

management

P0L.6, P0L.7

BUSTYP: CS0 Bus type configuration

1)

P0H.0

WRC Write/ Read configuration

1)

P0H.1, P0H.2

CSSEL: Chip Select

1)

P0H.3, P0H.4

SALSEL: CS0 Address Lines

1)

P0H.5.. P0H.7

CLKCFG: Clock configuration

1)

See Section 2: Clock

management