A.1 Bootstrap Code For The Dsp56305 - Motorola DSP56305 User Manual

Bootstrap Code
A.1 BOOTSTRAP CODE FOR THE DSP56305
This is a listing of the default bootstrap code for the DSP56305, which is normally
contained in the Bootstrap ROM. The user may modify or replace this with customized
code. Contact your Motorola representative for more information.
BOOTSTRAP CODE FOR DSP56305 - (C) Copyright 1996 Motorola Inc.
; Revised June 18, 1996.
;
; Bootstrap through the Host Interface, External EPROM or SCI.
;
; This is the Bootstrap
; ROM. This program can
; EPROM, from the
; execute a boot sequence from a user defined
; (RTOS) ROM.
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=x000,
; will start fetching instructions
; or $008000 (MD=1)
; used. The accesses will be performed using
; address attributes selected (default area).
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=0001-0111,
; of the RTOS ROM (address $FF0800).
; the RTOS ROM according to the values of MA, MB and MC in OMR.
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=1001,
; consecutive byte-wide
; 7-0). The memory is selected by the
; accessed with 31 wait states.
;
; The EPROM bootstrap
; number of program
; start loading the program words
; to be loaded. The number of words, the starting address
; words are read
; then by the most significant byte.
;
; The program words
; contiguous PRAM
; address. After
; from the same address where loading started.
;
;
A-2
program contained
load any program RAM segment
Host Interface or from the
then the Boot ROM is bypassed
beginning with address $C00000 (MD=0)
assuming that an external memory of SRAM type is
then the bootstrap program jumps to the head
The program flow then continues from
then it loads
P memory locations,
code expects first to read 3 bytes
words, afterwards
and then 3 bytes for each program word
least significant
will be condensed
memory locations starting at the
reading the program words, program
DSP56305 User's Manual
in the DSP56305 192-word Boot
SCI serial interface, or can
Real Time
and the DSP56305
31 wait states with no
a program RAM segment
starting at P:$D00000
Address Attribute
3 bytes specifying
byte first followed by the mid and
into 24-bit words and stored in
specified starting
from an external
Operating System
from
(bits
AA1 and is
specifying the
the address to
and the program
execution starts
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