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8210C–AVR–09/11
Atmel AVR XMEGA D
3.14
Register Descriptions
3.14.1
CCP – Configuration Change Protection register
• Bit 7:0 – CCP[7:0]: Configuration Change Protection
The CCP register must be written with the correct signature to enable change of the protected
I/O register or execution of the protected instruction for a maximum period of four CPU instruc-
tion cycles. All interrupts are ignored during these cycles. After these cycles, interrupts will
automatically be handled again by the CPU, and any pending interrupts will be executed accord-
ing to their level and priority. When the protected I/O register signature is written, CCP[0] will
read as one as long as the protected feature is enabled. Similarly when the protected SPM/LPM
signature is written, CCP[1] will read as one as long as the protected feature is enabled.
CCP[7:2] will always read as zero.
shows the signature for the various
modes.
3.14.2
RAMPZ – Extended Z-Pointer register
The RAMPZ is concatenated with the Z-register when reading (ELPM) program memory loca-
tions 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 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.
3.14.3
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
ECALL/EIJMP are used, and it will not be used if CALL and IJMP commands are used. For jump
Bit
7
6
5
4
3
2
1
0
CCP[7:0]
CCP
Read/Write
W
W
W
W
W
W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Table 3-1.
Modes of CPU change protection.
Signature
Group Configuration
Description
0x9D
SPM
Protected SPM/LPM
0xD8
IOREG
Protected IO register
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