Operating Modes
Core Configuration
4
-5
7
0 1
1
1
$FF0000
HI08 bootstrap in MC68302 bus mode
The bootstrap program loads the program RAM from
the Host Interface programmed to operate in the
MC68302 bus mode, in single-strobe pin
configuration. The HOST MC68302 bootstrap code
expects accesses that are byte wide. The HOST
MC68302 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.
8
1
0
0
0
$008000
Expanded mode
Bypasses the bootstrap ROM, and the DSP56303
starts fetching instructions beginning at address
$008000. Memory accesses are performed using
SRAM memory access type with 31 wait states and
no address attributes selected.
9
1
0
0
1
$FF0000
Bootstrap from byte-wide memory
The bootstrap program it loads a program RAM
segment from consecutive byte-wide P memory
locations, starting at P:$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 are 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.
Table 4-1. DSP56303 Operating Modes (Continued)
Mode
MODD
MODC
MODB
MODA
Reset
Vector
Description
Summary of Contents for DSP56303
Page 1: ...DSP56303 User s Manual 24 Bit Digital Signal Processor DSP56303UM AD Revision 1 January 2001 ...
Page 52: ...JTAG OnCE Interface 2 22 DSP56303 User s Manual ...
Page 114: ...General Purpose Input Output GPIO 5 10 DSP56303 User s Manual ...
Page 212: ...GPIO Signals and Registers 8 26 DSP56303 User s Manual ...
Page 268: ...Interrupt Equates A 22 DSP56303 User s Manual ...
Page 306: ...Programming Sheets B 38 DSP56303 User s Manual ...
Page 320: ...Index 14 DSP56303 User s Manual ...