Freescale Semiconductor DSP56366 - Manual (Page 253)

DSP56366 24-Bit Digital Signal Processor User Manual, Rev. 4
Freescale Semiconductor A-1
Appendix A Bootstrap ROM Contents
A.1 DSP56366 Bootstrap Program
; BOOTSTRAP CODE FOR DSP56366 Rev. 0 silicon - (C) Copyright 1999 Motorola Inc.
;
;
; Revision 0.0 1999/JAN/26 - Modified from 56362_RevA_regular_boot_rev01.asm:
; - Change the length of xram and the length of yram
; in burn-in code
; - Change the address of the reserved area in the
; Program ROM to $FFAF80 - $FFAFFF
;
; Revision 0.1 1999/MAR/29 - Enabled 100ns I2C filter in bootstrap
; mode 0110.
; - Added 5 NOP instructions after OnCE enable.
;
; This is the Bootstrap program contained in the DSP56366 192-word Boot
; ROM. This program can load any program RAM segment from an external
; EPROM, from the Host Interface or from the SHI serial interface.
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=x000, then the Boot ROM is bypassed and the DSP56366
; will start fetching instructions beginning with address $C00000 (MD=0)
; or $008000 (MD=1) assuming that an external memory of SRAM type is
; used. The accesses will be performed using 31 wait states with no
; address attributes selected (default area).
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=0001, then it loads a program RAM segment from consecutive
; byte-wide P memory locations, starting at P:$D00000 (bits 7-0).
; The memory is selected by the Address Attribute AA1 and is accessed with
; 31 wait states.
; The EPROM bootstrap code expects to read 3 bytes
; specifying the number of program words, 3 bytes specifying the address
; to start loading the program words and then 3 bytes for each program
; word to be loaded. The number of words, the starting address and the
; program words are read least significant byte first followed by the
; mid and then by the most significant byte.
; The program words will be condensed into 24-bit words and stored in
; contiguous PRAM memory locations starting at the specified starting address.
; After reading the program words, program execution starts from the same
; address where loading started.
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; If MD:MC:MB:MA=0010, then the bootstrap code jumps to the internal