15
XMEGA A [MANUAL]
8077I–AVR–11/2012
3.14.3 RAMPX – Extended X-Pointer register
This register is concatenated with the X-register for indirect addressing (LD/LDD/ST/STD) of the whole data memory
space on devices with more than 64KB of data memory. This register is not available if the data memory, including
external memory, is less than 64KB.
Bit 7:0 – RAMPX[7:0]: Extended X-pointer Address bits
These bits hold the MSB of the 24-bit address created by RAMPX and the 16-bit X-register. Only the number of bits
required to address the available data memory is implemented for each device. Unused bits will always read as zero.
3.14.4 RAMPY – Extended Y-Pointer register
This register is concatenated with the Y-register for indirect addressing (LD/LDD/ST/STD) of the whole data memory
space on devices with more than 64KB of data memory. This register is not available if the data memory, including
external memory, is less than 64KB.
Bit 7:0 – RAMPY[7:0]: Extended Y-pointer Address bits
These bits hold the MSB of the 24-bit address created by RAMPY and the 16-bit Y-register. Only the number of bits
required to address the available data memory is implemented for each device. Unused bits will always read as zero.
3.14.5 RAMPZ – Extended Z-Pointer register
This register is concatenated with the Z-register for indirect addressing (LD/LDD/ST/STD) of the whole data memory
space on devices with more than 64KB of data memory. RAMPZ is concatenated with the Z-register when reading
(ELPM) program memory locations above the first 64KB and writing (SPM) program memory locations above the first
128KB of the program memory.
This register is not available if the data memory, including external memory and program memory in the device, is less
than 64KB.
Bit 7:0 – RAMPZ[7:0]: Extended Z-pointer Address bits
These bits hold the MSB of the 24-bit address created by RAMPZ and the 16-bit Z-register. Only the number of bits
required to address the available data and program memory is implemented for each device. Unused bits will always
read as zero.
Bit
76543
210
+0x09
RAMPX[7:0]
Read/Write
R/W
Initial Value
0
Bit
765
43
21
0
+0x0A
RAMPY[7:0]
Read/Write
R/W
Initial Value
000
00
0
Bit
76543
210
+0x0B
RAMPZ[7:0]
Read/Write
R/W
Initial Value
00000
000