ATMEGA329P-20MN Atmel, ATMEGA329P-20MN Datasheet - Page 56

• Manufacturer Part Number: ATMEGA329P-20MN
• Description: IC MCU AVR 32K 20MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA329P-20MN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

11.2.1
8021G–AVR–03/11
Moving Interrupts Between Application and Boot Space
The General Interrupt Control Register controls the placement of the Interrupt Vector table. See
”MCUCR – MCU Control Register” on page
To avoid unintentional changes of Interrupt Vector tables, a special write procedure must be fol-
lowed to change the IVSEL bit:
1. Write the Interrupt Vector Change Enable (IVCE) bit to one.
2. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE.
Interrupts will automatically be disabled while this sequence is executed. Interrupts are disabled
in the cycle IVCE is set, and they remain disabled until after the instruction following the write to
IVSEL. If IVSEL is not written, interrupts remain disabled for four cycles. The I-bit in the Status
Register is unaffected by the automatic disabling.
Note:
The following example shows how interrupts are moved.
0x3804/0x7804
...
0x382C/0x782C
;
0x382E/0x782ERESET:ldir16,high(RAMEND); Main program start
0x382F/0x782F
0x3830/0x7830
0x3831/0x7831
0x3832/0x7832
0x3833/0x7833
If Interrupt Vectors are placed in the Boot Loader section and Boot Lock bit BLB02 is programmed,
interrupts are disabled while executing from the Application section. If Interrupt Vectors are placed
in the Application section and Boot Lock bit BLB12 is programed, interrupts are disabled while
executing from the Boot Loader section. Refer to the section
Write Self-Programming” on page 281
jmp
...
jmp
out
ldi
out
sei
<instr> xxx
PCINT0
...
SPM_RDY
SPH,r16
r16,low(RAMEND)
SPL,r16
; Store Program Memory Ready Handler
for details on Boot Lock bits.
57.
; Set Stack Pointer to top of RAM
; PCINT0 Handler
;
; Enable interrupts
ATmega329P/3290P
”Boot Loader Support – Read-While-
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