AT90USB64/128
memory locations. The operation of Boot Program section and associated Boot Lock bits for
software protection are described in detail in “Memory Programming” on page 368. “Memory
Programming” on page 368 contains a detailed description on Flash data serial downloading
using the SPI pins or the JTAG interface.
Constant tables can be allocated within the entire program memory address space (see the LPM
– Load Program Memory instruction description and ELPM - Extended Load Program Memory
instruction description).
Timing diagrams for instruction fetch and execution are presented in “Instruction Execution Tim-
ing” on page 14.
Figure 5-1. Program Memory Map
Program Memory
0x00000
Application Flash Section
Boot Flash Section
Flash End
5.2
SRAM Data Memory
Figure 5-2 shows how the AT90USB64/128 SRAM Memory is organized.
The AT90USB64/128 is a complex microcontroller with more peripheral units than can be sup-
ported within the 64 location reserved in the Opcode for the IN and OUT instructions. For the
Extended I/O space from $060 - $1FF in SRAM, only the ST/STS/STD and LD/LDS/LDD instruc-
tions can be used.
The first 4,608/8,704 Data Memory locations address both the Register File, the I/O Memory,
Extended I/O Memory, and the internal data SRAM. The first 32 locations address the Register
file, the next 64 location the standard I/O Memory, then 416 locations of Extended I/O memory
and the next 8,192 locations address the internal data SRAM.
19
7593A–AVR–02/06
ATMEL [ ATMEL ]
