Nano SPI device - takes SPI input and allows read/write of IO pins and SRAM registero.

All SPI commands are 4 bit long, arg is 4 bits CMD: ARG: Definition: STATUS field Returns status for the specific field SET IO pin Sets the specified output pin CLEAR IO pin Clears the specified output pin TARGET reg/addr/io Specify the target for read/write operations WRITE data Writes to the set target READ n/a Reads from the set target

CMD_STATUS 4'h0 CMD_SET 4'h1 CMD_CLEAR 4'h2 CMD_TARGET 4'h3 CMD_WRITE 4'h4 CMD_READ 4'h5