ESP8266 datasheet(44/117 Pages) ESPRESSIF

Part #	ESP8266

Description	General Purpose Input/Output Interface (GPIO)

PDF	117 Pages

Scroll/Zoom	100%

Manufacturer	ESPRESSIF [ESPRESSIF SYSTEMS (SHANGHAI) CO., LTD.]

Direct Link	https://www.espressif.com/

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44 / 117 page

4. SPI Communication User Guide

3. Master read data from the status register of the slave.

4. Master writes data to the status register of the slave.

The slave will receive interrupts in order from SPI_SLV_WR_BUF_DONE,

SPI_SLV_RD_BUF_DONE, SPI_SLV_RD_STA_DONE, SPI_SLV_WR_STA_DONE.

4.5.3.1. Hardware Connection

Figure 4-3. Test Demo Hardware Connection

Figure 4-3 shows the test demo hardware connection. The master and the slave are

connected via HSPI. MTCK pin is SPI. MOSI, MTDI pin is SPI MISO, MTMS pin is SPI Clock

and MTMO pin is SPI CS pin.

4.5.3.2. Program Introduction

spi_master_test

Master uses SPI buffer starting from W0.

void ICACHE_FLASH_ATTR spi_master_test()

{

SpiAttr hSpiAttr;

hSpiAttr.bitOrder = SpiBitOrder_MSBFirst;

hSpiAttr.speed = SpiSpeed_10MHz;

hSpiAttr.mode = SpiMode_Master;

hSpiAttr.subMode = SpiSubMode_0;

// Init HSPI GPIO

WRITE_PERI_REG(PERIPHS_IO_MUX, 0x105);

PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, 2);//configure io to spi

mode

ESP8266 Master

MTDI

MTCK

MTMS

MTDO

MTDI

MTCK

MTMS

MTDO

ESP8266 Slave

Espressif

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2017.05

ESP8266 Datasheet(PDF) 44 Page - ESPRESSIF SYSTEMS (SHANGHAI) CO., LTD.