16
8331B–AVR–03/12
Atmel AVR XMEGA AU
• 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 concat-
enated 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 mem-
ory 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.
3.14.6
EIND – Extended Indirect register
This register is concatenated with the Z-register for enabling extended indirect jump (EIJMP)
and call (EICALL) to the whole program memory space on devices with more than 128KB of pro-
gram memory. The register should be used for jumps to addresses below 128KB if
Bit
7
6
5
4
3
2
1
0
RAMPX[7:0]
RAMPX
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
RAMPY[7:0]
RAMPY
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
RAMPZ[7:0]
RAMPZ
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
