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8. HSPI Host Multi-device API

void hspi_dev_sel(uint8 dev_no)

Parameters

• uint8 dev_no: only HSPI_CS_DEV, SPI_CS1_DEV, SPI_CS2_DEV, and SPI_CS0_FLASH

are supported, the corresponding values of these four parameters are 0, 1, 2, and 3

respectively. If the parameter should be other values, ERROR will be printed and the

function will be returned.

• uint8 clk_polar: clock polarity.

If the clock polarity is 0, data are captured on the clock’s rising edge, and are

propagated on a falling edge.

If the clock polarity is 1, data are captured on the clock’s falling edge, and are

propagated on a rising edge.

If the clock polarity should be other values, ERROR will be printed and the function will

be returned.

• uint8 clk_div: clock frequency division. 40 MHz is reference frequency, the number of

division is clk_div+1. To be more speciﬁc, 0 stands for reference frequency, 1 stands for 20

MHz, while 2 stands for 40/3 MHz, and so forth.

⚠ Notice:

ONLY when the clock frequency of SPI bus used for reading Flash data is set at 80 MHz. If the device is

deﬁned by SPI_CS1_DEV and SPI_CS2_DEV via SPI OVERLAP, the clock frequency of host SPI is

unadjustable, and should be 80 MHz.

Function

Convert and select host communication devices.

Location

Deﬁned in directory

\app\include\driver\spi_overlap.h, implemented in directory

\app\driver\spi_overlap.c.

Parameters

uint8 dev_no: only HSPI_CS_DEV, SPI_CS1_DEV, SPI_CS2_DEV, and SPI_CS0_FLASH

are supported, the corresponding values of these four parameters are 0, 1, 2, and 3

respectively. If the device has not been initialized, ERROR will be printed and the function will

be returned. If it the parameter should be other values, ERROR will be printed and the

function will be returned.

Espressif

! /!

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2017.05

ESP8266 Datasheet(PDF) 74 Page - ESPRESSIF SYSTEMS (SHANGHAI) CO., LTD.