Rainbow Electronics DS89C450 - Manual (Page 20)

DS89C430/DS89C440/DS89C450 Ultra-High-Speed Flash Microcontrollers
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Figure 6. Memory Map (as shown for the DS89C430)
External
Data
Memory
8K x 8
Flash
Memory
(Program)
1K x 8
SRAM
Data OR
prog mem
addr from
400 - 7FF
128 Bytes
Indirect
Addressing
Bit Addressable
Bank 3
Bank 2
Bank 1
Bank 0
00
1F
20
2F
7F
80
128 Bytes SFR
FF
0000
1FFF
2000
3FFF
INTERNAL
MEMORY
03FF
0000
FFFF FFFF
4000
0000 0000
03FF
External
Program
Memory
INTERNAL
REGISTERS
8K x 8
Flash
Memory
(Program)
Memory Configuration
As illustrated in Figure 6 , the DS89C430 incorporates two 8kB flash areas for on-chip program memory and 1kB of
SRAM for on-chip data memory or a particular range (400–7FF) of “alternate” program memory space. The
DS89C440 incorporates two 16kB flash memories and the DS89C450 incorporates two 32kB flash memories. The
DS89C430 uses an address scheme that separates program memory from data memory such that the 16-bit
address bus can address each memory area up to maximum of 64kB.