7.1 Interfacing with Host Microcontroller

This section describes how to interface the ATWILC3000A with the host microcontroller. The interface comprises of a Client SPI/SDIO and additional control signals, as shown in Figure 7-1. Additional control signals are connected to the GPIO/IRQ interface of the microcontroller.

Figure 7-1. Interfacing with the Host Microcontroller

Table 7-1. Host Microcontroller Interface Pins
IC Pin#	Function⁽¹⁾
13	RESETN
14	BT_TXD
15	BT_RXD
16	BT_RTS
17	BT_CTS
27	CHIP_EN
29	SD_CLK
30	SD_CMD/SPI_SCK
31	SD_DAT0/SPI_TXD
32	SD_DAT1/SPI_SSN
34	SD_DAT2/SPI_RXD
35	SD_DAT3
40	IRQN

Note:

Logic input for IC pin SDIO_SPI_CFG(#12) determines whether SDIO or SPI Client interface is enabled.
- Connect SDIO_SPI_CFG to VDDIO through a 1 MΩ resistor to enable the SPI interface.
- Connect SDIO_SPI_CFG to ground to enable the SDIO interface.
Adding test points for the IC pins BT_TXD (#14), BT_RXD (#15), BT_RTS (#16), BT_CTS (#17), UART_TXD (#22) and UART_RXD (#23) in the design is recommended.