SPI-Lite SPI Master Interface

Github: http://github.com/ultraembedded/cores

This component is a simple SPI Master mode implementation with AXI4-Lite slave interface. The register interface has limited compatibility with Xilinx's SPI peripheral IP, enough so that the Linux Kernel SPI driver works with it unmodified.

Features

• All combinations of SPI Master modes (CPHA, CPOL) supported.
• 8 slaves support (8 chip select lines).
• 4 entry Tx/Rx FIFOs.
• 8-bit SPI data unit size.
• LSB or MSB data first option.
• Loopback test mode supported.
• AXI4-L register interface.
• Interrupt output (on Tx-empty / Rx valid).

Limitations

• SPI Master only
• Manual chip select mode only.
• AXI4-L address and data must arrive in the same cycle.

Testing

Verified under simulation then tested on FPGA against various SPI flash parts under Linux using the stock Linux Kernel 4.19 driver (spi-xilinx.c).

Configuration

• parameter C_SCK_RATIO - Clock divider ratio for clk_i -> spi_clk_o

References

• LogiCORE IP AXI Serial Peripheral Interface (AXI SPI) (v1.01a)