An SPI master interface with AMBA AXI 3.0 interface is designed for PKU-DSPⅡ single chip

which supports four transfer modes

variable frame length

frequency programmable clock output and five interrupt types.Simultaneously

the bootrom program for the RISC DSP is also proposed

providing normal booting from external FLASH and system updating of the boot-loader codes in the external FLASH.Both the function simulation and FPGA prototyping show that PKU-DSPⅡ can boot and conduct system updating through the external FLASH successfully

which provides good evidence for the correctness of the design of the SPI master interface and the bootrom program.The design has been implemented with CSMC 0.18μm CMOS technology for taping out.