Motorola DSP56303 User Manual page 70

24-bit digital signal processor
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Operating Modes
Table 4-1. DSP56303 Operating Modes (Continued)
Mode
MODD
MODC
5
0
1
6
0
1
4-4
Reset
MODB
MODA
Vector
0
1
$FF0000
1
0
$FF0000
DSP56303 User's Manual
Description
HI08 bootstrap in HC11 nonmultiplexed mode
The bootstrap program sets the host interface to
interface with the Motorola HC11 microcontroller
through the HI08. The HOST HC11 bootstrap code
expects to read a 24-bit word specifying the number
of program words, a 24-bit word specifying the
address to start loading the program words and then
a 24-bit word for each program word to be loaded.
The program words are stored in contiguous P RAM
memory locations starting at the specified starting
address. After reading the program words, program
execution starts from the same address where
loading started. The Host Interface bootstrap load
program may be stopped by setting the Host Flag 0
(HF0). This starts execution of the loaded program
from the specified starting address.
HI08 bootstrap in 8051 multiplexed bus mode
The bootstrap program sets the host interface to
interface with the Intel 8051 bus through the HI08.
The HI08 pin configuration is optimized for
connection to the Intel 8051 multiplexed bus, in
double-strobe pin configuration. The HOST 8051
bootstrap code expects accesses that are byte wide.
The HOST 8051 bootstrap code expects to read 3
bytes forming a 24-bit word specifying the number of
program words, 3 bytes forming a 24-bit word
specifying the address to start loading the program
words and then 3 bytes forming 24-bit words for each
program word to be loaded. The program words are
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. The
Host Interface bootstrap load program may be
stopped by setting the Host Flag 0 (HF0). This starts
execution of the loaded program from the specified
starting address. The base address of the HI08 in
multiplexed mode is $80 and is not modified by the
bootstrap code. All the address lines are enabled
and should be connected accordingly.

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