"Simple SPI" SPI controller RTL

http://opencores.org/project,simple_spi

The core has had a variable-width slave-select register and corresponding I/O 
lines added.

There is also optional boot-up logic, that sends a series of bus-commands upon 
reset, initialising, say a SPI flash chip, to read-state. This could potentially
save space in any bootloader code or FSM wishing to read from an SPI-bus chip 
at boot time. Defparam the 'startup_state_reset' to 4'h10 to enable it, and 
see the RTL for more details.

