maybe the document of GPIO Pin sensing mechanism has some wrong.

Question

maybe the document of GPIO Pin sensing mechanism has some wrong in the nRF51 Series Reference Manual (version 1.1). 
 sense high/low level defined in the document is different from the code of SDK 9.0.0. 
 high level is 1, low is 2; 
 PIN_CNF[n] (n=0..31):
E RW SENSE Pin sensing mechanism
DISABLED 0 Disabled
HIGH 1 Sense for high level
LOW 2 Sense for low level 
 code of sdk 9.0.0: high level is 2, low is 1; 
 /** 
 
 @enum nrf_gpio_pin_sense_t 
 @brief Enumerator used for selecting the pin to sense high or low level on the pin input.
*/ 
 
 typedef enum
{ 
 NRF_GPIO_PIN_NOSENSE = GPIO_PIN_CNF_SENSE_Disabled, ///< Pin sense level disabled. 
 NRF_GPIO_PIN_SENSE_LOW = GPIO_PIN_CNF_SENSE_Low, ///< Pin sense low level.

NRF_GPIO_PIN_SENSE_HIGH = GPIO_PIN_CNF_SENSE_High, ///< Pin sense high level.
 
 } nrf_gpio_pin_sense_t;

Vidar Berg · Accepted Answer

Hi, thanks for reporting this, but this is fixed in the latest revision of the nRF51 RM that I checked. 
 From the nrf51_bitfields header: 
 
 GPIO_PIN_CNF_SENSE_Disabled (0x00UL) /*!< Disabled. */ 
 GPIO_PIN_CNF_SENSE_High (0x02UL) /*!< Wakeup on high level. */ 
 GPIO_PIN_CNF_SENSE_Low (0x03UL) /*!< Wakeup on low level. */