On-Chip Memory; Off-Chip Memory Expansion; Table 1-2 On Chip Memory; Memory Configuration - Motorola DSP56309 User Manual

DSP56309 Overview
DSP56300 Core Functional Blocks
The OnCE module provides a means of interacting with the DSP56300 core and its
peripherals non-intrusively so that a user can examine registers, memory, or on-chip
peripherals. This facilitates hardware and software development on the DSP56300 core
processor. OnCE module functions are provided through the JTAG TAP signals. More
information about the OnCE module is provided in Section 10ÑOn-Chip Emulation
Module
.
1.6.6

On-Chip Memory

The memory space of the DSP56300 core is partitioned into program memory space,
X data memory space, and Y data memory space. The data memory space is divided into
X data memory and Y data memory in order to work with the two Address ALUs and to
feed two operands simultaneously to the Data ALU. Memory space includes internal
RAM and ROM and can be expanded off-chip under software control. More information
about the internal memory is provided in Section 3ÑMemory Configuration.
Program RAM, instruction cache, X data RAM, and Y data RAM size are programmable,
as indicated in Table 1-2.
Instruction Switch
Cache
disabled disabled
enabled disabled
disabled enabled
enabled enabled
There is an on-chip 192 x 24-bit bootstrap ROM.
1.6.7

Off-Chip Memory Expansion

Memory can be expanded off-chip to do the following:
¥ Data memory expansion to two 256K ´ 24-bit word memory spaces (or up to two
M ´ 24-bit word memory spaces by using the address attribute AA0ÐAA3 signals)
¥ Program memory expansion to one 256K ´ 24-bit words memory space (or up to
4 M ´ 24-bit word memory space by using the address attribute AA0ÐAA3 signals)
one
Additional features of off-chip memory include the following:
1-12

Table 1-2 On Chip Memory

Program RAM
Mode Size
20K ´ 24-bit
19K´ 24-bit
24K ´ 24-bit
23K ´ 24-bit
DSP56309UM/D
Instruction X Data RAM
Cache Size Size
7K ´ 24-bit
0
1K ´ 24-bit 7K ´ 24-bit
5K ´ 24-bit
0
1K ´ 24-bit 5K ´ 24-bit
Y Data RAM
Size
7K ´ 24-bit
7K ´ 24-bit
5K ´ 24-bit
5K ´ 24-bit
4
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