ATMEGA128A datasheet(14/369 Pages) ATMEL

部品番号	ATMEGA128A

部品情報	8-bit Microcontroller with 128Kbytes

Download	369 Pages

Scroll/Zoom	100%

メーカー	ATMEL [ATMEL Corporation]

ホームページ	http://www.atmel.com

Logo

14 / 369 page

14

ATmega 128A [DATASHEET]

Atmel-8151I-8-bit-AVR-ATmega128A_Datasheet-08/2014

Figure 6-3.

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).

6.6

Stack Pointer

The Stack is mainly used for storing temporary data, for storing local variables and for storing return addresses

after interrupts and subroutine calls. Note that the Stack is implemented as growing from higher to lower

memory locations. The Stack Pointer Register always points to the top of the Stack. The Stack Pointer points to

the data SRAM Stack area where the Subroutine and Interrupt Stacks are located. A Stack PUSH command will

decrease the Stack Pointer.

The Stack in the data SRAM must be defined by the program before any subroutine calls are executed or

interrupts are enabled. Initial Stack Pointer value equals the last address of the internal SRAM and the Stack

Pointer must be set to point above start of the SRAM, see Figure 7-2 on page 21.

See Table 6-1 for Stack Pointer details.

The Atmel®AVR® Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of bits

actually used is implementation dependent. Note that the data space in some implementations of the AVR

architecture is so small that only SPL is needed. In this case, the SPH Register will not be present.

15

XH

XL

0

X - register

7

0

7

0

R27 ($1B)

R26 ($1A)

15

YH

YL

0

Y - register

7

0

7

0

R29 ($1D)

R28 ($1C)

15

ZH

ZL

0

Z - register

7

0

7

0

R31 ($1F)

R30 ($1E)

Table 6-1.

Stack Pointer instructions

Instruction

Stack pointer

Description

PUSH

Decremented by 1

Data is pushed onto the stack

CALL

ICALL

RCALL

Decremented by 2

Return address is pushed onto the stack with a subroutine call or

interrupt

POP

Incremented by 1

Data is popped from the stack

RET

RETI

Incremented by 2

Return address is popped from the stack with return from

subroutine or return from interrupt

同様の部品番号 - ATMEGA128A

メーカー	部品番号	データシート	部品情報
ATMEL Corporation	ATMEGA128A	561Kb / 22P	8-bit Microcontroller with 128K Bytes In-System Programmable Flash
	ATMEGA128A	7Mb / 386P	Write/Erase cycles: 10,000 Flash/100,000 EEPROM
	ATMEGA128A-AU	561Kb / 22P	8-bit Microcontroller with 128K Bytes In-System Programmable Flash
	ATMEGA128A-AUR	561Kb / 22P	8-bit Microcontroller with 128K Bytes In-System Programmable Flash
	ATMEGA128A-MU	561Kb / 22P	8-bit Microcontroller with 128K Bytes In-System Programmable Flash

More results

同様の説明 - ATMEGA128A

メーカー	部品番号	データシート	部品情報
ATMEL Corporation	ATMEGA128-16AN	481Kb / 24P	8-bit Atmel Microcontroller with 128KBytes In-System Programmable Flash
	AT90USB646-AU	11Mb / 456P	8-bit Atmel Microcontroller with 64/128Kbytes of ISP Flash and USB Controller
	AT90USB646-MU	11Mb / 456P	8-bit Atmel Microcontroller with 64/128Kbytes of ISP Flash and USB Controller
	ATMEGA128	481Kb / 24P	Microcontroller with 128KBytes In-System Programmable Flash Rev. 2467XS-AVR-06/11
Holtek Semiconductor In...	HT827A0	302Kb / 49P	8-Bit Microcontroller with Voice ROM
Integral Corp.	IZ7008	445Kb / 16P	8-BIT MICROCONTROLLER WITH LCD DRIVER
ELAN Microelectronics C...	EM78458	399Kb / 62P	8-Bit Microcontroller with MASK ROM
	EM78156E	420Kb / 48P	8-Bit Microcontroller with MASK ROM
	EM78P153K	903Kb / 68P	8-Bit Microcontroller with OTP ROM
	EM78P163N	700Kb / 82P	8-Bit Microcontroller with OTP ROM