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Bootstrap Code
HI08CONT
bset
jclr
movep
jclr
movep
move
do
HI08LL
jset
jump
jclr
the
enddo
bra
HI08NW
movep
HI08LOOP
bra
;========================================================================
EPRSCILD
jclr #1,omr,EPROMLD
;========================================================================
; This is the routine that loads from the SCI.
; MC:MB:MA=010 - external SCI clock
SCILD
movep #$0302,X:M_SCR
A-6
; HRP
= 0 Negative host request
; HCSP
= 0 Negative chip select input
; HD/HS
= 0 Single strobe bus (R/W~ and DS strobes)
; HMUX
= 0 Non multiplexed bus
; HASP
= 0 (address strobe polarity has no meaning in
;
non-multiplexed bus)
; HDSP
= 0 Negative data strobes polarity
; HROD
= 0 Host request is active when enabled
; spare = 0 This bit should be set to 0 for future
;
compatibility
; HEN
= 0 When the HPCR register is modified HEN should be
;
cleared
; HAEN
= 1 Host acknowledge is enabled
; HREN
= 1 Host requests are enabled
; HCSEN = 1 Host chip select input enabled
; HA9EN
= 0 (address 9 enable bit has no meaning in
;
non-multiplexed bus)
; HA8EN
= 0 (address 8 enable bit has no meaning in
;
non-multiplexed bus)
; HGEN
= 0 Host GPIO pins are disabled
#HEN,x:M_HPCR
#HRDF,x:M_HSR,*
x:M_HRX,a0
#HRDF,x:M_HSR,*
x:M_HRX,r0
r0,r1
a0,HI08LOOP
#HRDF,x:M_HSR,HI08NW
#HF0,x:M_HSR,HI08LL
<HI08LOOP
x:M_HRX,p:(r0)+
<FINISH
; If MC:MB:MA=001, go load from EPROM
; Configure SCI Control Reg
DSP56303 User's Manual
; Enable the HI08 to operate as host
; interface (set HEN=1)
; wait for the program length to be
; written
; wait for the program starting address
; to be written
; set a loop with the downloaded length
;
counts
; If new word was loaded then
;to read that word
; If HF0=0 then continue with
; downloading
; Must terminate the do loop
; Move the new word into its destination
; location in the program RAM
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