Rainbow Electronics AT90LS4433 - Manual (Page 12)

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AT90S/LS4433
1042G–AVR–09/02
The direct addressing reaches the entire data space. The Indirect with Displacement
mode features 63 address locations reached from the base address given by the Y- or
Z-register.
When using register indirect addressing modes with automatic pre-decrement and post-
increment, the address registers X, Y, and Z are decremented and incremented.
The 32 general purpose working registers, 64 I/O Registers and the 128 bytes of inter-
nal data SRAM in the AT90S4433 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 AT90S4433 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 supported 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 registers r (Rr) and d (Rd). The result is stored in register d
(Rd).