.include "spi.h65" Export spi_p, begin, end, read, pages_written, bytes_written .zeropage code_page: .res 2 ; CODE_START + pages_written * 256 .bss bytes_written: .res 1 pages_written: .res 1 SPI_IO := spi_p::SPI_IO CODE_START := spi_p::CODE_START ; spi-transferred code will be placed here ; SPI_P = as peripheral .code .struct SPI_P_Pins ; VIA addresses DDR_a .word ; address of the data direction register R_a .word ; address of the register ; pin mask SCLK_p .byte ; Serial Clock POCI_p .byte ; Peripheral Out / Controller In PICO_p .byte ; Peripheral In / Controller Out CSB_p .byte ; Chip Select ; settings CPOL .byte ; Clock Polarity CPHA .byte ; Clock Phase .endstruct ;******************************************************************************** ; @function Begin listening for SPI transfers ; @details ; - initialize variables ; - configure shift register to shift in under external clock ; - enable shift register interrupts ;******************************************************************************** .proc begin stz pages_written stz bytes_written ; store address in zp lda #CODE_START sta code_page + 1 ; todo USE MASKS ; set Shift register to shift in under external clock on CB1 lda #IO::ACR::SR_SIN_PHIE sta SPI_IO + IO::ACR ; enable SR interrupts lda #(IO::IRQ::IRQ | IO::IRQ::SR) sta SPI_IO + IO::IER ; load SR to reset lda SPI_IO + IO::SR rts .endproc ;******************************************************************************** ; @function Stop listening for SPI transfers ; @details ; Disables shift register interrupts ;******************************************************************************** .proc end ; disable SR interrupts lda #IO::IRQ::SR sta SPI_IO + IO::IER rts .endproc ;******************************************************************************** ; @function Read a byte from SPI ; @details ; Reads a byte from the shift register and stores it in the SPI code buffer ;******************************************************************************** .proc read ldx bytes_written lda SPI_IO + IO::SR sta CODE_START,x inc bytes_written beq @new_page rts @new_page: inc pages_written inc code_page + 1 rts .endproc ;******************************************************************************** ; @function Initialize the IO Adapter for SPI ; @param ARG0-1 Address of the SPI_Pins struct ;******************************************************************************** ;******************************************************************************** ; @function Read bytes ; @param X Number of bytes to send ; @param ARG0-1 Address of the SPI_Pins struct ; @param ARG2-3 Address of the first byte ;******************************************************************************** .proc recv_data .endproc ;******************************************************************************** ; @function Send bytes ; @param X Number of bytes to send ; @param ARG0-1 Address of the SPI_Pins struct ; @param ARG2-3 Address of the first byte ;******************************************************************************** .proc send_data .endproc