3-6
DSP56309UM/D MOTOROLA
Memory Configuration
RAM Configuration
Memory maps for the different configurations are shown in
.
Note:
The MS bit cannot be changed when CE is set. The instruction cache occupies
the top 1K of what would otherwise be Program RAM; if you switch memory
into or out of Program RAM when the cache is enabled, the switch causes
conflicts. To change the MS bit when CE is set, do the following:
1. Clear CE.
2. Change MS.
3. Set CE.
3.2.1
On-Chip Program Memory (Program RAM)
The on-chip Program RAM consists of 24-bit wide, high-speed, internal Static RAM
occupying the lowest 20K (default), 23K, 24K, or 19K locations in the program memory
space (depending on the settings of the MS and CE bits). The Program RAM default
organization is 80 banks of 256 24-bit words (20K). The upper eight banks of both X data
RAM and Y data RAM can be configured as Program RAM by setting the MS bit. When
the CE is set, the upper 1K of Program RAM is used as an internal Instruction Cache.
CAUTION
While the contents of Program RAM are unaffected by toggling the
MS bit, the location of program data placed in the Program
RAM/Instruction Cache area changes after the MS bit is toggled, since
the cache always occupies the top-most 1K Program RAM addresses.
To preserve program data integrity, do not set or clear the MS bit
when the CE bit is set. See Section 3.2 on page 3-5 for the correct
procedure.
3.2.2
On-Chip X Data Memory (X Data RAM)
The on-chip X data RAM consists of 24-bit wide, high-speed, internal Static RAM
occupying the lowest 7K (default) or 5K locations in the X memory space. The size of the
X data RAM depends on the setting of the MS bit (default: MS is cleared). The X data
RAM default organization is 28 banks of 256 (7K) 24-bit words. Eight banks of RAM can
be switched from the X data RAM to the Program RAM by setting the MS bit (leaving 5K
of X data RAM).
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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