Motorola DSP56305 User Manual page 562

Bootstrap Code
; with single-strob pin configuration (RD/WR,DS).
; MD:MC:MB:MA=1111 - Host UB
UB1HOSTLD
bset #13,x1
;========================================================================
; This is the routine that loads from the Host Interface in UB (UNIVERSAL) mode,
; with double-strobe pin configuration (RD,WR).
; MD:MC:MB:MA=1110 - Host UB
UB2HOSTLD
movep x1,X:M_DCTR
do #6,_LOOP0
jclr #2,X:M_DSR,*
movep X:M_DRXR,a2
asr #8,a,a
_LOOP0
move a1,r0
move a1,r1
; Download P memory through UB
do a0,_LOOP1
do #3,_LOOP2
_LBLA
jset #2,X:M_DSR,_LBLB
jclr #3,X:M_DSR,_LBLA
enddo
bra <TERMINATE
_LBLB
movep X:M_DRXR,a2
asr #8,a,a
_LOOP2
movem a1,p:(r0)+
nop
_LOOP1
bra <FINISH
;========================================================================
IHOSTLD
jclr #0,omr,PCIHOSTLD
;========================================================================
; This routine loads from the Host Interface in ISA (UNIVERSAL) mode.
; MD:MC:MB:MA=1101 - Host ISA
; Using self configuration mode, the base address in CBMA is written with
; $2f which corresponds to an ISA HTXR address of $2fe (Serial Port 2 Modem
; Status read only register).
ISAHOSTLD
A-8
; HDSM=1 (Double-strob pin mode disabled)
; Configure HI32 in UB mode Single or Double strobe
; read # of words and start address
; Wait for SRRQ to go high (i.e. data ready)
;
; Shift 8 bit data into A1
;
; starting address for load
; save it in r1
; a0 holds the number of words
; Load instruction words
; for each byte
; Wait for SRRQ to go high (i.e. data ready)
; If HF0=1, stop loading new data.
; Must terminate the do loop
; Terminate loop (enddo) and finish
; Store 16-bit data in accumulator
; Shift 8 bit data into A1
; and go get another 24-bit word.
; Store 24-bit data in P mem
; movem cannot be at LA.
; and go get another 24-bit word.
; finish bootstrap
; If MD:MC:MB:MA=1100, go load from PCI HOST
DSP56305 User's Manual MOTOROLA