STMPE821 datasheet(24/55 Pages) STMICROELECTRONICS

Part #	STMPE821

Description	8-bit Xpander Logic??with touchkey controller

PDF	55 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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24 / 55 page

GPIO controller

STMPE821

24/55

The function of each bit is shown in the following table:

Table 9.

GPIO control bits function

Function

GPIO monitor pin state

Reading this bit yields the current state of the bit. Writing has no

effect.

GPIO set pin state

Writing '1' to this bit causes the corresponding GPIO to go to '1' state

Writing '0' to this bit causes the corresponding GPIO to go to '0' state

GPIO set pin direction

'0' sets the corresponding GPIO to input state, and '1' sets it to output

state. All bits are '0' on reset. The GPIO must be set as output if the

PWM on this pin is to be used.

GPIO function

'1' sets the corresponding GPIO to function as GPIO/PWM, and '0'

sets it to touchkey direct output mode.

For GPIO 0-3, if the GPIO function is set to GPIO/PWM mode and the

AF bits in the PWM master enable register is enabled, the

corresponding GPIO will function as PWM output.

STMPE821 Datasheet(PDF) 24 Page - STMicroelectronics