GPIO Blink (BK) and Serial Blink (SBK)

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Certain GPIOs are capable of supporting Blink (BK) and Serial Blink (SBK). The BK and SBK are implemented as native functions muxed on selected GPIOs. To enable BK or SBK on a GPIO having the capability, BIOS needs to select the BK or SBK native function on the GPIO.

Blink, also referred to as Pulse Width Modulator (PWM), provides a programmable PWM wave. The Blink/PWM frequency and duty cycle are programmable through the PWM Control Register. Refer to Volume 2 for the related register.

Serial Blink, also referred to as Serial POST Codes, allows system software to serialize POST or other messages to a serial monitor. The Serial Blink message is programmed through the Serial Blink Command/Status and Serial Blink Data Registers. Refer to Volume 2 for the related registers.

GPIO Ownership

SCI / SMI and NMI GPIO Ownership