I/O usage

The nRF51822-QFAA has 31 generic I/Os available. All I/Os are used in this design and are organized as shown in table below.

Table 1. I/O usage
I/O Label Description
P0.00 DEBUG HALF  
P0.01 DEBUG FULL  
P0.02 I2C_DATA_2 Two-wire 2 master data
P0.03 I2S LRCLK ADC audio data left and right
P0.04 I2S MCLK Master clock
P0.05 I2C_CLK_2 Two-wire 2 master clock
P0.06 I2S DOUT ADC audio data
P0.07 I2C_CLK Two-wire 1 master clock
P0.08 KEYIN_0 Input from keypad row 0
P0.09 KEYIN_1 Input from keypad row 1
P0.10 KEYIN_2 Input from keypad row 2
P0.11 KEYIN_3 Input from keypad row 3
P0.12 I2S SCLK Audio data bit clock
P0.13 I2S SCLK Audio data bit clock
P0.14 P0.14 Connected to P0.15
P0.15 P0.15 Connected to P0.14
P0.16 Power switch Control signal power switch
P0.17 KEYIN_4 Input from keypad row 4
P0.18 ICM-20608_INT Motion tracking device interrupt
P0.19 KEYOUT_0 Output to keypad column 0
P0.20 KEYOUT_1 Output to keypad column 1
P0.21 KEYOUT_2 Output to keypad column 2
P0.22 KEYOUT_3 Output to keypad column 3
P0.23 KEYOUT_4 Output to keypad column 4
P0.24 KEYOUT_5 Output to keypad column 5
P0.25 KEYOUT_6 Output to keypad column 6
P0.26 XL1 32.768 kHz crystal
P0.27 XL2 32.768 kHz crystal
P0.28 KEYOUT_7 Output to keypad column 7
P0.29 LIS3DH_INT1 Low-power accelerometer interrupt 1
P0.30 I2C_DATA Two-wire 1 master data
Parent topic: Design description