WHC Interface and Hardware Configuration

WHC Interface Connections

The pin connections between Ameba and Raspberry Pi are as follows:

Interface	Ameba SoC pin	Raspberry Pi GPIO	Function
SDIO	PB6	GPIO 26	SDIO_DAT2
	PB7	GPIO 27	SDIO_DAT3
	PB8	GPIO 23	SDIO_CMD
	PB9	GPIO 22	SDIO_CLK
	PB13	GPIO 24	SDIO_DAT0
	PB14	GPIO 25	SDIO_DAT1
SPI	PB24	GPIO 10	SPI_MOSI
	PB25	GPIO 9	SPI_MISO
	PB23	GPIO 11	SPI_CLK
	PB26	GPIO 8	SPI_CS
	PB8	GPIO 23	DEV_TX_REQ
	PB9	GPIO 22	DEV_READY

Note

SPI DEV_TX_REQ: Ameba notifies Host of pending data transmission via rising edge on this pin
SPI DEV_READY: Ameba status indicator
- High level (1): Device ready to receive data
- Low level (0): Device busy (pause transmission)

Note

Default SDIO pins defined in Ameba SDK are used. If modification is required, adjust the SDIO_Pin_Grp parameter in the files below, which corresponds to the pinmux index in SDIO_PAD :

file location： component/soc/usrcfg/amebadplus/ameba_intfcfg.c
Host-side SDIO interrupt requirements:
- By default, SDIO_DATA1 is used.
- If the Host does not support SDIO interrupts:
  - It can switch to polling mode for communication.
  - If the Host requires GPIO-based interrupts: The Ameba platform provides limited configurable GPIOs for this functionality. For detailed configurations and supported GPIO lists, currently request, please contact us.

Default configuration uses Ameba SDK predefined dedicated SPI pins. For custom pin configuration, refer to Pin Multiplexing Table to select pins and follow these steps below:

Dedicated Pin Configuration

Modify the corresponding code in component/wifi/whc/whc_dev/spi/whc_spi_drv.h:

#elif defined (CONFIG_AMEBADPLUS)
#define PINMUX_FUNCTION_SPIS      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_9
#define RX_REQ_PIN                _PB_8
#define SPIS_MOSI                 _PB_24
#define SPIS_MISO                 _PB_25
#define SPIS_SCLK                 _PB_23
#define SPIS_CS                   _PB_26

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIS      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIS_MOSI                 _PA_29
#define SPIS_MISO                 _PA_30
#define SPIS_SCLK                 _PA_28
#define SPIS_CS                   _PA_31

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIS      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIS_MOSI                 _PA_29
#define SPIS_MISO                 _PA_30
#define SPIS_SCLK                 _PA_28
#define SPIS_CS                   _PA_31

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIS      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIS_MOSI                 _PA_29
#define SPIS_MISO                 _PA_30
#define SPIS_SCLK                 _PA_28
#define SPIS_CS                   _PA_31

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIS      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIS_MOSI                 _PA_29
#define SPIS_MISO                 _PA_30
#define SPIS_SCLK                 _PA_28
#define SPIS_CS                   _PA_31

If switching to SPI1 (SDK uses SPI0 as the default), modify the following code in the same file:

#define WHC_SPI_DEV               SPI0_DEV
#define SPIS_IRQ                  SPI0_IRQ

#define WHC_SPI_DEV               SPI0_DEV
#define SPIS_IRQ                  SPI0_IRQ

#define WHC_SPI_DEV               SPI0_DEV
#define SPIS_IRQ                  SPI0_IRQ

#define WHC_SPI_DEV               SPI0_DEV
#define SPIS_IRQ                  SPI0_IRQ

#define WHC_SPI_DEV               SPI0_DEV
#define SPIS_IRQ                  SPI0_IRQ

Full-matrix Pin Configuration

For differences between dedicated pins and full-matrix pins, refer to Function Multiplexing .

When using full-matrix pins, after completing the above Dedicated Pin configuration:

In component/wifi/whc/whc_dev/spi/whc_spi_drv.c, modify the PinFuncID parameter of Pinmux_Config(PinName, PinFuncID) to match full matrix signal IDs:

void whc_spi_dev_device_init(void)
{
   ...
   /* Initialize SPI */
   Pinmux_Config(SPIS_MOSI, PINMUX_FUNCTION_SPIS);//MOSI
   Pinmux_Config(SPIS_MISO, PINMUX_FUNCTION_SPIS);//MISO
   Pinmux_Config(SPIS_SCLK, PINMUX_FUNCTION_SPIS);//CLK
   Pinmux_Config(SPIS_CS, PINMUX_FUNCTION_SPIS);//CS
   PAD_PullCtrl(SPIS_CS, GPIO_PuPd_UP);  // pull-up, default 1
   PAD_PullCtrl(SPIS_SCLK, GPIO_PuPd_DOWN);
   ...
}

Adjust host frequency (refer to SPI Peripheral for full-matrix pins requirements)

File path: component/wifi/whc/whc_host_linux/common/spi/spidev-overlay.dts

fragment@3 {
   target = <&spi0>;
   __overlay__ {
            status = "okay";
            #address-cells = <1>;
            #size-cells = <0>;
            inic_spi: inic_spi@0 {
            compatible = "realtek,inic";
            reg = <0>;
            spi-max-frequency = <30000000>;
            status = "okay";
         };
   };
};

File path: component/wifi/whc/whc_host_rtos/spi/whc_spi_host.h

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIM      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIM_MOSI                 _PA_29
#define SPIM_MISO                 _PA_30
#define SPIM_SCLK                 _PA_28
#define HOST_READY_PIN            _PA_31
#define SPI_CLOCK_DIVIDER         6   // 120M clock source according to spi_get_ipclk

Configuration Example

Using RTL8713E as example, select full-matrix pins from Pin Multiplexing Table :

SoC pin	PinFuncID
PA_21	SPI1_MOSI
PA_12	SPI1_MISO
PA_11	SPI1_MISO
PA_23	SPI1_CS

Update SPI configuration in component/wifi/whc/whc_dev/spi/whc_spi_drv.h:

#define SPIS_MOSI                 _PA_21
#define SPIS_MISO                 _PA_12
#define SPIS_SCLK                 _PA_11
#define SPIS_CS                   _PA_23

#define WHC_SPI_DEV               SPI1_DEV
#define SPIS_IRQ                  SPI1_IRQ

Update pin multiplexing in component/wifi/whc/whc_dev/spi/whc_spi_drv.c:

void whc_spi_dev_device_init(void)
{
   ...
   /* Initialize SPI */
   Pinmux_Config(SPIS_MOSI, PINMUX_FUNCTION_SPI1_MOSI);//MOSI
   Pinmux_Config(SPIS_MISO, PINMUX_FUNCTION_SPI1_MISO);//MISO
   Pinmux_Config(SPIS_SCLK, PINMUX_FUNCTION_SPI1_CLK);//CLK
   Pinmux_Config(SPIS_CS, PINMUX_FUNCTION_SPI1_CS);//CS
   PAD_PullCtrl(SPIS_CS, GPIO_PuPd_UP);  // pull-up, default 1
   PAD_PullCtrl(SPIS_SCLK, GPIO_PuPd_DOWN);
   ...
}

Host frequency adjustment examples:

File path: component/wifi/whc/whc_host_linux/common/spi/spidev-overlay.dts

fragment@3 {
   target = <&spi0>;
   __overlay__ {
            status = "okay";
            #address-cells = <1>;
            #size-cells = <0>;
            inic_spi: inic_spi@0 {
            compatible = "realtek,inic";
            reg = <0>;
            spi-max-frequency = <10000000>;
            status = "okay";
         };
   };
};

File path: component/wifi/whc/whc_host_rtos/spi/whc_spi_host.h

#elif defined (CONFIG_AMEBALITE)
#define PINMUX_FUNCTION_SPIM      PINMUX_FUNCTION_SPI
#define DEV_READY_PIN             _PB_3
#define RX_REQ_PIN                _PB_2
#define SPIM_MOSI                 _PA_29
#define SPIM_MISO                 _PA_30
#define SPIM_SCLK                 _PA_28
#define HOST_READY_PIN            _PA_31
#define SPI_CLOCK_DIVIDER         12   // 120M clock source according to spi_get_ipclk

WHC SDIO Adapter Board

Realtek provides adapter board that enables convenient connection to mini SD card slots. It is recommended to use dedicated adapter boards for interfacing with SDIO pins.

../../_images/sdio_adapter_board.jpg — WHC SDIO adapter board (physical diagram)

Note

Realtek official adapter boards will be available soon. Currently request samples, please contact us.

WHC Raspberry Pi Direct Connection

For high-speed scenarios, directly solder Ameba SDIO pins to Raspberry Pi GPIO.

../../_images/connection_with_raspberry_pi.jpg — Ameba-Raspberry Pi direct connection diagram