Datasheet

19
8018P–AVR–08/10
ATmega169P
6.8.1 The X-register, Y-register, and Z-register
The registers R26..R31 have some added functions to their general purpose usage. These reg-
isters are 16-bit address pointers for indirect addressing of the data space. The three indirect
address registers X, Y, and Z are defined as described in Figure 6-5.
Figure 6-5. The X-, Y-, and Z-registers
In the different addressing modes these address registers have functions as fixed displacement,
automatic increment, and automatic decrement (see the instruction set reference for details).
15 XH XL 0
X-register 707 0
R27 (0x1B) R26 (0x1A)
15 YH YL 0
Y-register 707 0
R29 (0x1D) R28 (0x1C)
15 ZH ZL 0
Z-register 7070
R31 (0x1F) R30 (0x1E)