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7593L–AVR–09/12
AT90USB64/128
6.
Atmel AVR AT90USB64/128 memories
This section describes the different memories in the AT90USB64/128. The AVR architecture has
two main memory spaces, the Data Memory and the Program Memory space. In addition, the
AT90USB64/128 features an EEPROM Memory for data storage. All three memory spaces are
linear and regular.
Notes:
1. Byte address.
2. Word (16-bit) address.
6.1
In-system re-programmable flash program memory
The AT90USB64/128 contains 128Kbytes On-chip In-System Re-programmable Flash memory
for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is organized as
64K × 16. For software security, the Flash Program memory space is divided into two sections,
Boot Program section and Application Program section.
The Flash memory has an endurance of at least 100,000 write/erase cycles. The
AT90USB64/128 Program Counter (PC) is 16 bits wide, thus addressing the 128K program
memory locations. The operation of Boot Program section and associated Boot Lock bits for
Table 6-1.
Memory mapping.
Memory
Mnemonic
AT90USB64
AT90USB128
Flash
Size
Flash size
64Kbytes
128K bytes
Start address
-
0x00000
End address
Flash end
32 registers
Size
-
32bytes
Start address
-
0x0000
End address
-
0x001F
I/O registers
Size
-
64 bytes
Start address
-
0x0020
End address
-
0x005F
Ext I/O
registers
Size
-
160bytes
Start address
-
0x0060
End address
-
0x00FF
Internal
SRAM
Size
ISRAM size
4Kbytes
8Kbytes
Start address
ISRAM start
0x0100
End address
ISRAM end
0x10FF
0x20FF
External
Memory
Size
XMem size
0-64Kbytes
Start address
XMem start
0x1100
0x2100
End address
XMem end
0xFFFF
EEPROM
Size
E2 size
2Kbytes
4Kbytes
Start address
-
0x0000
End address
E2 end
0x07FF
0x0FFF