Motorola DSP56303, User Manual, Page: 26 / 320

Internal Buses
1 -10 DSP56303 User’s Manual
1.5.7 Off-Chip Memory Expansion
Memory can be expanded off chip to the following capacities:
■
Data memory expansion to two 256 K
×
24-bit word memory spaces using the standard
external address lines
■
Program memory expansion to one 256 K
×
24-bit words memory space using the
standard external address lines
Further features of off-chip memory include the following:
■
External memory expansion port
■
Simultaneous glueless interface to static random access memory (SRAM) and dynamic
random access memory (DRAM)
1.6 Internal Buses
To provide data exchange between the blocks, the DSP56303 implements the following
buses:
■
Peripheral I/O expansion bus to peripherals
■
Program memory expansion bus to program ROM
■
X memory expansion bus to X memory
■
Y memory expansion bus to Y memory
■
Global data bus between PCU and other core structures
■
Program data bus for carrying program data throughout the core
■
X memory data bus for carrying X data throughout the core
■
Y memory data bus for carrying Y data throughout the core
■
Program address bus for carrying program memory addresses throughout the core
■
X memory address bus for carrying X memory addresses throughout the core
■
Y memory address bus for carrying Y memory addresses throughout the core.
The block diagram in Figure 1-1 illustrates these buses among other components.