DSP56002 OPERATING MODES
MOTOROLA
MEMORY MODULES AND OPERATING MODES
3 - 9
In the bootstrap mode, the chip enables the bootstrap ROM and executes the bootstrap
program. (The bootstrap program code is shown in Appendix A.) The bootstrap ROM con-
tains the bootstrap firmware program that performs initial loading of the DSP56002
program RAM. Written in DSP56002 assembly language, the program initializes the pro-
gram RAM by loading from an external byte-wide EPROM starting at location P:$C000.
The EPROM is typically connected to the chip’s address and data bus.The data contents
of the EPROM must be organized as shown in Table 3-3 Organization of EPROM Data
Contents.
ADDRESS OF EXTERNAL
BYTE-WIDE P MEMORY
P:$C000
P:$C001
P:$C002
•
•
•
P:$C5FD
P:$C5FE
P:$C5FF
CONTENTS LOADED
TO INTERNAL P: RAM AT:
P:$0000 LOW BYTE
P:$0000 MID BYTE
P:$0000 HIGH BYTE
•
•
•
P:$01FF LOW BYTE
P:$01FF MID BYTE
P:$01FF HIGH BYTE
Figure 3-3 Port A Bootstrap Circuit
DSP56002
11
8
CE
A0-A10
D0-D7
2716
PS
A0-A10
D0-D7
Notes: 1. *These diodes must be Schottky diodes.
2. All resistors are 15K
Ω
unless noted otherwise.
3. When in RESET, IRQA, IRQB and NMI must
be deasserted by external peripherals.
MODA/IRQA
RESET
MODB/IRQB
MBD301
*
MBD301
*
+5 V
FROM OPEN
COLLECTOR
BUFFER
FROM
RESET
FUNCTION
FROM OPEN
COLLECTOR
BUFFER
BR
HACK
MBD301
*
MODC/NMI
WT
DR
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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