Atmel AVR User Manual

90. PUSH – Push Register on Stack
90.1. Description
This instruction stores the contents of register Rr on the STACK. The Stack Pointer is post-decremented
by 1 after the PUSH.
This instruction is not available in all devices. Refer to the device specific instruction set summary.
Operation:
(i) STACK ← Rr
Syntax: Operands: Program Counter: Stack:
(i) PUSH Rr 0 ≤ r ≤ 31 PC ← PC + 1 SP ← SP - 1
16-bit Opcode:
1001 001d dddd 1111
90.2. Status Register (SREG) and Boolean Formula
I T H S V N Z C
– – – – – – – –
Example:
call routine ; Call subroutine
...
routine: push r14 ; Save r14 on the Stack
push r13 ; Save r13 on the Stack
...
pop r13 ; Restore r13
pop r14 ; Restore r14
ret ; Return from subroutine
Words 1 (2 bytes)
Cycles 2
Cycles XMEGA 1
Atmel AVR Instruction Set Manual [OTHER]
Atmel-0856L-AVR-Instruction-Set-Manual_Other-11/2016
136

Atmel AVR Specifications

General

Architecture	8-bit RISC
SRAM	Up to 16 KB
Clock Speed	Up to 20 MHz
Operating Voltage	1.8V to 5.5V
ADC	10-bit ADC
Communication Interfaces	SPI, I2C, USB
Packages	DIP, SOIC, QFN
Special Features	Watchdog Timer
Flash Memory	1KB to 256KB
EEPROM	64B to 4KB