The interrupt line (DAT1) is an extra pin comparing to SD memory, allowing the slave to actively inform the host some events. It's possible for two ESP32 chips to communicate with each other in 1-bit mode or SPI mode without the DAT1 line by polling the slave's interrupt registers. But this will increase the CPU load of the host, and do harm to the response speed to slave events.
65 lines
2.6 KiB
Text
65 lines
2.6 KiB
Text
menu "Example Configuration"
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config EXAMPLE_SDIO_OVER_SPI
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bool "Host use SPI bus to communicate with slave"
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default n
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help
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If this is set, the host tries using SPI bus to communicate with slave.
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Otherwise, the standarad SD bus is used.
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config EXAMPLE_SDIO_4BIT
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bool "Host tries using 4-bit mode to communicate with slave"
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default n
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depends on !EXAMPLE_SDIO_OVER_SPI
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help
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If this is set, the host tries using 4-bit mode to communicate with
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slave. If failed, the communication falls back to 1-bit mode.
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If this is not set, the host uses 1-bit mode. However, CMD1 is still
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mandatory for interrupts.
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Note that 4-bit mode is not compatible (by default) if the slave is
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using 3.3V flash which requires a pull-down on the MTDI pin.
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config EXAMPLE_SDIO_HIGHSPEED
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bool "Host tries using HS mode to communicate with slave"
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default y
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help
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If this is set, the host tries using high-speed mode to communicate
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with slave. If the slave doesn't support high-speed mode, the
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communication falls back to default-speed mode. If this is not set,
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the host uses DS mode.
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If the example does not work, please try disabling the HS mode.
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config EXAMPLE_NO_INTR_LINE
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bool "The host is not connected to the interrupt line (DAT1) of slave"
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default n
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help
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If this is set, the host example will not check the interrupt line but poll slave
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registers to see whether the slave has interrupts for the host.
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Working without the interrupt line may increase the CPU load of the host, and do harm
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to the response speed to slave events, though can save 1 GPIO for other purposes in
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non-4-bit mode.
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choice EXAMPLE_SLAVE
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prompt "GPIO to control slave EN in Espressif master-slave board."
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default EXAMPLE_SLAVE_NONE
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help
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If Espressif master-slave board is used, select the correct GPIO to control slave's EN.
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config EXAMPLE_SLAVE_NONE
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bool "Not using Espressif master-slave board."
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config EXAMPLE_SLAVE_B1
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bool "Using slave B1"
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endchoice
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config EXAMPLE_SLAVE_PWR_NEGTIVE_ACTIVE
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bool "Slave power control pin is negtive active, otherwise postive active"
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depends on !EXAMPLE_SLAVE_NONE
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default n
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help
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Slave power control pin is negtive active, otherwise postive active
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endmenu
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