UM1574 datasheet(28/48 Pages) STMICROELECTRONICS

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Hardware and layout

UM1574

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Doc ID 023645 Rev 1

4.3.2

STM8AL board LEDs

The STM8AL board includes the following LEDs and their description is:

LD1 COM: LD1 default status is red. LD1 turns to green to indicate that communications are

in progress between the PC and the ST-LINK/V2.

LD2 PWR: red LED indicates that the board is powered and that 3.3 V is generated by the

regulator supplied by the L99PM62GXP power management IC.

User LD3: red LED is a user LED connected to the I/O PE7 of the STM8AL3L68T.

User LD4: green LED is a user LED connected to the I/O PC7 of the STM8AL3L68T.

4.3.3

STM8AL board Push buttons

The STM8AL board includes two push buttons:

●

USER1: User button connected to the I/O PE1 of STM8AL3L68T.

●

USER2: User button connected to the I/O PE2 of STM8AL3L68T.

4.3.4

STM8AL board built-in IDD measurement circuit

The STM8AL board built-in IDD measurement circuit allows the consumption of the

STM8AL3L68T to be measured and displayed on the LCD Glass while the MCU is in Run or

Low power saving modes.

●

JP2 in ON position: STM8AL3L68T is powered through IDD measurement circuit

(default).

●

JP2 in OFF position: STM8AL3L68T is powered directly by +3V3, IDD measurement

circuit is bypassed.

Note: When jumper JP2 is removed the current consumption of the STM8AL3L68T can be

measured by connecting an ammeter between jumper JP2 pin 1 and pin 2.

For IDD measurement by the MCU itself, the circuit below is implemented on the STM8AL

board. Solder bridges SB6, SB7 and SB8 must be closed and a jumper must be plugged

between JP2 pin 2 and pin 3.

UM1574 Datasheet(PDF) 28 Page - STMicroelectronics