Meaning of ''FM+ capable''

[martinpetkovic]

Posted on June 19, 2013 at 16:25

Hello to everyone!

What does it mean the ''FM+ capable'' feature of a pin? There is 5V tolerant, and 5 V tolerant I/O, FM+, pin (STM32F051x4 datasheet - pin PB6, PB7, PB8, PB9) and what is the diference? This feature isn't mentioned anywhere.

Thank You.

#high-current #aggresive

[Tesla DeLorean]

Posted on June 19, 2013 at 16:54

The I/O speed configuration is bypassed in FM+ I/O mode. Refer to the STM32F05xxx reference manual RM0091 for a

description of FM+ I/O mode configuration.

..

The high sink LED driver capability (only available on the PB9 pin) can be activated through

the I2C_PB9_FM+ bit in the SYS_CTRL register and used to sink the high current needed

to directly control an infrared LED.

..

20 mA output drive for FM+ mode

..

Bits 19:16 I2C_PBx_FM+: Fast Mode Plus (FM+) driving capability activation bits.

These bits are set and cleared by software. Each bit enables I2C FM+ mode for PB6, PB7,

PB8, and PB9 I/Os.

0: PBx pin operates in standard mode.

1: I2C FM+ mode enabled on PBx pin, and the Speed control is bypassed.