INTRODUCTION
A - 4
BOOTSTRAP AND ROM CODE
MOTOROLA
; BOOTSTRAP CODE FOR DSP56002 - (C) Copyright 1990 Motorola Inc.
; Revised October 24, 1990.
;
; Bootstrap through the Host Interface, External EPROM or SCI.
;
;
BOOT
EQU
$C000
; this is the location in P memory
; on the external memory bus
; where the external byte-wide
; EPROM would be located
PBC
EQU
$FFE0
; Port B Control Register
HSR
EQU
$FFE9
; Host Status Register
HRX
EQU
$FFEB
; Host Receive Register
PCC
EQU
$FFE1
; Port C Control Register
SCR
EQU
$FFF0
; SCI Control Register
SSR
EQU
$FFF1
; SCI Status Register
SCCR
EQU
$FFF2
; SCI Clock Control Register
SRXL
EQU
$FFF4
; SCI Receive Register Low
STXL
EQU
$FFF4
; SCI Transmit Register Low
ORG
PL:$0,PL:$0
; bootstrap code starts at $0
START
MOVE
#<0,R0
; default P address where prog
; will begin loading
JCLR
#4,OMR,EPROMLD
; If MC:MB:MA=0xx, go load from EPROM
JSET
#1,OMR,SCILD
; If MC:MB:MA=11x, go load from SCI
; This routine loads from the Host Interface.
; MC:MB:MA=100 - reserved
; MC:MB:MA=101 - Host
HOSTLD
BSET
#0,X:PBC
; Configure Port B as Host
DO
#512,_LOOP3
; Load 512 instruction words
_LBLA
JCLR
#3,X:HSR,_LBLB
; if HF0=1, stop loading data.
ENDDO
; Must terminate the do loop
JMP <_LOOP3
_LBLB
JCLR
#0,X:HSR,_LBLA
; Wait for HRDF to go high
; (meaning data is present).
MOVEP X:HRX,P:(R0)+
; Store 24-bit data in P mem.
_LOOP3
; and go get another 24-bit word.
JMP
<FINISH
; finish bootstrap
Figure A-1 DSP56002 Bootstrap Program (Sheet 1 of 3)
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