| ; Author: Frederik Noring <noring@nocrew.org> | 
 | ; | 
 | ; This file is subject to the terms and conditions of the GNU General Public | 
 | ; License.  See the file COPYING in the main directory of this archive | 
 | ; for more details. | 
 |  | 
 | ; DSP56k loader | 
 |  | 
 | ; Host Interface | 
 | M_BCR   EQU     $FFFE           ; Port A Bus Control Register | 
 | M_PBC   EQU     $FFE0           ; Port B Control Register | 
 | M_PBDDR EQU     $FFE2           ; Port B Data Direction Register | 
 | M_PBD   EQU     $FFE4           ; Port B Data Register | 
 | M_PCC   EQU     $FFE1           ; Port C Control Register | 
 | M_PCDDR EQU     $FFE3           ; Port C Data Direction Register | 
 | M_PCD   EQU     $FFE5           ; Port C Data Register | 
 |  | 
 | M_HCR   EQU     $FFE8           ; Host Control Register | 
 | M_HSR   EQU     $FFE9           ; Host Status Register | 
 | M_HRX   EQU     $FFEB           ; Host Receive Data Register | 
 | M_HTX   EQU     $FFEB           ; Host Transmit Data Register | 
 |  | 
 | ; SSI, Synchronous Serial Interface | 
 | M_RX    EQU     $FFEF           ; Serial Receive Data Register | 
 | M_TX    EQU     $FFEF           ; Serial Transmit Data Register | 
 | M_CRA   EQU     $FFEC           ; SSI Control Register A | 
 | M_CRB   EQU     $FFED           ; SSI Control Register B | 
 | M_SR    EQU     $FFEE           ; SSI Status Register | 
 | M_TSR   EQU     $FFEE           ; SSI Time Slot Register | 
 |  | 
 | ; Exception Processing | 
 | M_IPR   EQU     $FFFF           ; Interrupt Priority Register | 
 |  | 
 |         org     P:$0 | 
 | start   jmp     <$40 | 
 |  | 
 |         org     P:$40 | 
 | ;       ; Zero 16384 DSP X and Y words | 
 | ;       clr     A #0,r0 | 
 | ;       clr     B #0,r4 | 
 | ;       do      #64,<_block1 | 
 | ;       rep     #256 | 
 | ;       move    A,X:(r0)+ B,Y:(r4)+ | 
 | ;_block1        ; Zero (32768-512) Program words | 
 | ;       clr     A #512,r0 | 
 | ;       do      #126,<_block2 | 
 | ;       rep     #256 | 
 | ;       move    A,P:(r0)+ | 
 | ;_block2 | 
 |  | 
 |         ; Copy DSP program control | 
 |         move    #real,r0 | 
 |         move    #upload,r1 | 
 |         do      #upload_end-upload,_copy | 
 |         movem    P:(r0)+,x0 | 
 |         movem    x0,P:(r1)+ | 
 | _copy   movep   #4,X:<<M_HCR | 
 |         movep   #$c00,X:<<M_IPR | 
 |         and     #<$fe,mr | 
 |         jmp     upload | 
 |  | 
 | real | 
 |         org     P:$7ea9 | 
 | upload | 
 |         movep   #1,X:<<M_PBC | 
 |         movep   #0,X:<<M_BCR | 
 |  | 
 | next    jclr    #0,X:<<M_HSR,* | 
 |         movep   X:<<M_HRX,A | 
 |         move    #>3,x0 | 
 |         cmp     x0,A #>1,x0 | 
 |         jeq     <$0 | 
 | _get_address | 
 |         jclr    #0,X:<<M_HSR,_get_address | 
 |         movep   X:<<M_HRX,r0 | 
 | _get_length | 
 |         jclr    #0,X:<<M_HSR,_get_length | 
 |         movep   X:<<M_HRX,y0 | 
 |         cmp     x0,A #>2,x0 | 
 |         jeq     load_X | 
 |         cmp     x0,A | 
 |         jeq     load_Y | 
 |  | 
 | load_P  do      y0,_load_P | 
 |         jclr    #0,X:<<M_HSR,* | 
 |         movep   X:<<M_HRX,P:(r0)+ | 
 | _load_P jmp     next | 
 | load_X  do      y0,_load_X | 
 |         jclr    #0,X:<<M_HSR,* | 
 |         movep   X:<<M_HRX,X:(r0)+ | 
 | _load_X jmp     next | 
 | load_Y  do      y0,_load_Y | 
 |         jclr    #0,X:<<M_HSR,* | 
 |         movep   X:<<M_HRX,Y:(r0)+ | 
 | _load_Y jmp     next | 
 |  | 
 | upload_end | 
 |         end |