DSP 56001 Host Communication Example

@DrWatson

Published in 

atari

 · 23 Nov 2023

This example illustrates a typical DSP Host communication program.

; DSP Host Port IO 
: Author: Fredrik Noring, 1994 

M_HSR   EQU     $FFE9        ; Host Status Register 
M_HRX   EQU     $FFEB        ; Host Receive Data Register 
M_HTX   EQU     $FFEB        ; Host Transmit Data Register 

          org    p:$0 
          jmp    <start 

          org    p:$40 
start     jsr    <Host_get   ; Receive Host data 
          move   #0.27,A     ; Move value to the 56-bits A register 
          move   #0.31415,y0 ; Move value to the 24-bits y0 register 
          mac    x0,y0,A     ; Multiply x0 and y0 and accumulate to A 
          move   A,x0        ; Move the A1 portion of A to x0 
          jsr    <Host_send  ; Send Host data 

          jmp    <start      ; Continue 

; Host I/O routines. 
Host_get  jclr    #0,X:<<M_HSR,<Host_get 
          movep   X:<<M_HRX,x0  ; Move 24-bits Host data to x0 
          rts 
Host_send jclr    #1,X:<<M_HSR,<Host_send    ; 
          movep   x0,X:<<M_HTX  ; Move x0 to 24-bits Host data 
          rts