
Bootstrap ROM
DSP56364 24-Bit Digital Signal Processor Users Manual, Rev. 2
A-2 Freescale Semiconductor
opt cex,mex,mu
;;
;;;;;;;;;;;;;;;;;;;; GENERAL EQUATES ;;;;;;;;;;;;;;;;;;;;;;;;
;;
BOOT equ $D00000 ; this is the location in P memory
; on the external memory bus
; where the external byte-wide
; EPROM would be located
AARV equ $D00409 ; AAR1 selects the EPROM as CE~
; mapped as P from $D00000 to
; $DFFFFF, active low
PROMADDR equ $FF1000 ; Starting PROM address
MA EQU 0
MB EQU 1
MC EQU 2
MD EQU 3
;;
;;;;;;;;;;;;;;;;;;;; DSP I/O REGISTERS ;;;;;;;;;;;;;;;;;;;;;;;;
;;
M_AAR1 EQU $FFFFF8 ; Address Attribute Register 1
M_HRX EQU $FFFF94 ; SHI Receive FIFO
M_HCSR EQU $FFFF91 ; SHI Control/Status Register
hrne equ 17 ; SHI FIFO Not Empty flag
hi2c equ 1 ; SHI I2C Enable Control Bit
hckfr equ 4 ; SHI I2C Clock Freeze Control Bit
ORG PL:$ff0000,PL:$ff0000 ; bootstrap code starts at $ff0000
START
clr a #$0,r5 ; clear a and init R5 with 0
jclr #MC,omr,OMRX0XX ; If MD:MC:MB:MA=x0xx, go to OMRX0XX
jset #MD,omr,SHILD ; If MD:MC:MB:MA=11xx, go load from SHI
jset #MB,omr,BURN_RES ; If MD:MC:MB:MA=011X, go to BURN/RESERV
jset #MA,omr,EPROMLD ; If MD:MC:MB:MA=0101, go load from EPROM
;========================================================================
; This is the routine that jumps to the internal Program ROM.
; MD:MC:MB:MA=0100
move #PROMADDR,r1 ; store starting PROM address in r1
bra <FINISH
;========================================================================
; This is the routine that loads from SHI.
; MD:MC:MB:MA=1100 - reserved
; MD:MC:MB:MA=1101 - Bootstrap from SHI (SPI slave)
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