ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 15

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

RAMPZ – Extended Z-pointer
Register for ELPM/SPM
EIND – Extended Indirect
Register
2549K–AVR–01/07
For ELPM/SPM instructions, the Z-pointer is a concatenation of RAMPZ, ZH, and ZL, as
shown in Figure 8. Note that LPM is not affected by the RAMPZ setting.
Figure 8. The Z-pointer used by ELPM and SPM
The actual number of bits is implementation dependent. Unused bits in an implementa-
tion will always read as zero. For compatibility with future devices, be sure to write these
bits to zero.
For EICALL/EIJMP instructions, the Indirect-pointer to the subroutine/routine is a con-
catenation of EIND, ZH, and ZL, as shown in Figure 9. Note that ICALL and IJMP are
not affected by the EIND setting.
Figure 9. The Indirect-pointer used by EICALL and EIJMP
The actual number of bits is implementation dependent. Unused bits in an implementa-
tion will always read as zero. For compatibility with future devices, be sure to write these
bits to zero.
Bit
0x3B (0x5B)
Read/Write
Initial Value
Bit (
Individually)
Bit (Z-pointer)
Bit
0x3C (0x5C)
Read/Write
Initial Value
Bit (Individual-
ly)
Bit
pointer)
(Indirect-
RAMPZ7
EIND7
R/W
R/W
7
0
7
0
23
23
7
7
RAMPZ6
EIND6
R/W
R/W
EIND
RAMPZ
ATmega640/1280/1281/2560/2561
6
0
6
0
RAMPZ5
EIND5
R/W
R/W
16
5
0
5
0
0
16
0
RAMPZ4
EIND4
R/W
R/W
4
0
4
0
15
7
15
7
RAMPZ3
EIND3
R/W
R/W
ZH
3
0
3
0
ZH
RAMPZ2
EIND2
R/W
R/W
2
0
2
0
0
8
0
8
RAMPZ1
EIND1
R/W
R/W
1
0
1
0
7
7
7
7
RAMPZ0
EIND0
R/W
R/W
ZL
0
0
0
0
ZL
RAMPZ
EIND
0
0
0
0
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