Bootstrap Code
Bootstrap Program
A
-7
movep #$C000,X:M_SCCR ; Configure SCI Clock Control Reg
movep #7,X:M_PCRE ; Configure SCLK, TXD and RXD
do #6,_LOOP6 ; get 3 bytes for number of
; program words and 3 bytes
; for the starting address
jclr #2,X:M_SSR,* ; Wait for RDRF to go high
movep X:M_SRXL,A2 ; Put 8 bits in A2
jclr #1,X:M_SSR,* ; Wait for TDRE to go high
movep A2,X:M_STXL ; echo the received byte
asr #8,a,a
_LOOP6
move a1,r0 ; starting address for load
move a1,r1 ; save starting address
do a0,_LOOP7 ; Receive program words
do #3,_LOOP8
jclr #2,X:M_SSR,* ; Wait for RDRF to go high
movep X:M_SRXL,A2 ; Put 8 bits in A2
jclr #1,X:M_SSR,* ; Wait for TDRE to go high
movep a2,X:M_STXL ; echo the received byte
asr #8,a,a
_LOOP8
movem a1,p:(r0)+ ; Store 24-bit result in P mem.
_LOOP7
bra <FINISH ; Boot from SCI done
;========================================================================
; This is the routine that loads from external EPROM.
; MC:MB:MA=001
EPROMLD
move #BOOT,r2 ; r2 = address of external EPROM
movep #AARV,X:M_AAR1 ; aar1 configured for SRAM types of access
do #6,_LOOP9 ; read number of words and starting address
movem p:(r2)+,a2 ; Get the 8 LSB from ext. P mem.
asr #8,a,a ; Shift 8 bit data into A1
_LOOP9 ;
move a1,r0 ; starting address for load
move a1,r1 ; save it in r1
; a0 holds the number of words
do a0,_LOOP10 ; read program words
do #3,_LOOP11 ; Each instruction has 3 bytes
movem p:(r2)+,a2 ; Get the 8 LSB from ext. P mem.
asr #8,a,a ; Shift 8 bit data into A1
_LOOP11 ; Go get another byte.
movem a1,p:(r0)+ ; Store 24-bit result in P mem.
_LOOP10 ; and go get another 24-bit word.
; Boot from EPROM done
;========================================================================
FINISH
; This is the exit handler that returns execution to normal
Содержание DSP56303
Страница 1: ...DSP56303 User s Manual 24 Bit Digital Signal Processor DSP56303UM AD Revision 1 January 2001 ...
Страница 52: ...JTAG OnCE Interface 2 22 DSP56303 User s Manual ...
Страница 114: ...General Purpose Input Output GPIO 5 10 DSP56303 User s Manual ...
Страница 212: ...GPIO Signals and Registers 8 26 DSP56303 User s Manual ...
Страница 268: ...Interrupt Equates A 22 DSP56303 User s Manual ...
Страница 306: ...Programming Sheets B 38 DSP56303 User s Manual ...
Страница 320: ...Index 14 DSP56303 User s Manual ...