Program And Data Addressing Modes - Atmel AVR AT90S2333 Manual

The 32 general purpose working registers, 64 I/O registers and the 128 bytes of internal data SRAM in the
AT90S2333/4433 are all accessible through all these addressing modes.
See the next section for a detailed description of the different addressing modes.

Program and Data Addressing Modes

The AT90S2333/4433 AVR RISC microcontroller supports powerful and efficient addressing modes for access to the Flash
program memory, SRAM, Register File, and I/O data memory. This section describes the different addressing modes sup-
ported by the AVR architecture. In the figures, OP means the operation code part of the instruction word. To simplify, not all
figures show the exact location of the addressing bits.
Register Direct, Single Register Rd
Figure 10. Direct Single Register Addressing
The operand is contained in register d (Rd).
Register Direct, Two Registers Rd and Rr
Figure 11. Direct Register Addressing, Two Registers
Operands are contained in register r (Rr) and d (Rd). The result is stored in register d (Rd).
AT90S/LS2333 and AT90S/LS4433
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