DSP56001FE33 MOTOROLA [Motorola, Inc], DSP56001FE33 Datasheet - Page 61

• Manufacturer Part Number: DSP56001FE33
• Description: 24-Bit General Purpose Digital Signal Processor
• Manufacturer: MOTOROLA [Motorola, Inc]

Motorola DSP56000 Macro Cross Assembler Version 2.00 87-08-23 09:57:46 bootcode.asm Page 2
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
DSP56001
P:0008
P:0009
P:000B
P:000C
0040F9
060082
00001B
0E6012
060380
000010
Figure E-2. Assembler Listing for Bootstrap Program (Sheet 2 of 3)
; changing modes, the program will load from external program memory.
; to bootstrap operating mode, make certain that the L bit is cleared and registers M0
; and M1have been set to $FFFF. Also, make sure the BCR is set to $xxFx since
; EPROMS are slow and BCR is set to $FFFF after a reset. If the L bit was set before
; The first routine will load 1,536 bytes from the external P: memory space beginning
; at P:$C000 (bits 7-0). These will be packed into 512 24-bit words and stored in
; contiguous internal PRAM memory locations starting at P:$0.
; The shifter moves the 8-bit input data from register A2 into register A1 eight bits
; at a time. After assembling one 24-bit word (this takes three loops) it stores the
; result in internal PRAM and continues until internal PRAM is filled. Note that the
; first routine loads data starting with the least significant byte of P:$0 first.
; The second routine loads the internal PRAM using the Host Interface logic.
; If the host only wants to load a portion of the PRAM, the Host Interface bootstrap
; load program can be aborted and execution of the loaded program started, by setting
; the Host Flag (HF0) = 1 at any time during the load from the Host Processor.
INLOOP
; This is the context switch
; This is the first routine. It loads from external P: memory.
ORI
D0
JLC
DO
#$40,CCR
#512,_LOOP1
< _HOSTLD
#3, _LOOP2
; Set the L bit to indicate
; that the bootstrap program
; is being loaded from the
; external P: space.
; Load 512 instruction words.
; Load from the Host Interface
; if the Limit flag is clear.
; Each instruction has 3 bytes.
MOTOROLA
E-61