Ram Memory Description; Dsp56156 Ram Part Memory Introduction - Motorola DSP56156 Manual

MODE 0 and 1
MB=0 MA=X
$FFFF
EXTERNAL
$7FF
INTERNAL
RAM
INTERNAL
(Write Only)
BOOT ROM
(Read Only) 0
RESET
0
0
3.1

RAM MEMORY DESCRIPTION

This part of the DSP56156 memory description describes the part that uses RAM memory
for the Program Memory . The memory of the DSP56156 can be partitioned in several
ways to provide high-speed parallel operation and additional off-chip memory expansion.
Program and data memory are separate. Both the program and data memories can be
expanded off-chip.
3.1.1

DSP56156 RAM Part Memory Introduction

The two independent memory spaces of the DSP56156, X data, and program, are shown
in Figure 3-1. The memory spaces are configured by control bits in the operating mode
register (OMR). The operating mode control bits (MA and MB) in the OMR control the pro-
gram memory map and select the reset vector address.
MOTOROLA OPERATING MODES AND MEMORY SPACES
RAM MEMORY DESCRIPTION
$FFFF
PROGRAM
MEMORY
SPACE
$3F
INTERRUPT
VECTORS
0
OPERATING MODE DETERMINES
PROGRAM MEMORY AND
RESET STARTING ADDRESS
MODE 2
MB=1 MA=0 MB=1 MA=1
$FFFF $FFFF
RESET
$E000
EXTERNAL
EXTERNAL
$7FF
INTERNAL
$3F
RAM
0
0
PRAM
EXTERNAL RESET EXTERNAL RESET
Figure 3-1 DSP56156 RAM Memory
$FFFF
DATA
MEMORY
SPACE
0
MODE 3
$FFFF
$FFC0
$7FF
RESET
PRAM
ON-CHIP
PERIPHER-
EXTERNAL
X DATA
MEMORY
INTERNAL
X RAM
0
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