Gpio; Functional Overview - Espressif ESP8266 Technical Reference

!
2.

2.1. Functional Overview

The ESP8266 has 16 general IOs. Their pin numbers and names are shown in the table
below:

GPIO0

GPIO1
GPIO2
GPIO3
GPIO4
GPIO5
GPIO6
GPIO7
GPIO8
GPIO9
GPIO10
GPIO11
GPIO12
GPIO13
GPIO14
GPIO15
In the QUAD mode flash, 6 IO interfaces are used for flash communication.
In the DUAL mode flash, 4 IO interfaces are used for flash communication.
! Note:
Users may find the following documents helpful:
Appendix 1 - GPIO Registers
•
List of ESP8266 pin functions: ESP8266_Pin_List.xlsx:
•
http://bbs.espressif.com/viewtopic.php?f=21&t=412&p=1545#p1545
Espressif
GPIO NO.
pin15
pin26
pin14
pin25
pin16
pin24
pin21
pin22
pin23
pin18
pin19
pin20
pin10
pin12
pin9
pin13
Table 2-1. GPIO Pin Definition
Pin NO.
! /! 6 86
GPIO
Pin name
GPIO0_U
U0TXD_U
GPIO2_U
U0RXD_U
GPIO4_U
GPIO5_U
SD_CLK_U
SD_DATA0_U
SD_DATA1_U
SD_DATA2_U
SD_DATA3_U
SD_CMD_U
MTDI_U
MTCK_U
MTMS_U
MTDO_U
2. GPIO
2016.05