ATmega32 Microcontroller

Data Sheet :
ATmega32

ATmega32 is very much similar to ATmega16 microcontroller with certain differences which are discussed below. ATmega32 is an 8-bit high performance microcontroller of Atmel’s Mega AVR family. Atmega32 is based on enhanced RISC (Reduced Instruction Set Computing) architecture with 131 powerful instructions. Most of the instructions execute in one machine cycle. Atmega32 can work on a maximum frequency of 16MHz.

 

The differences between ATmega32 and ATmega16 can be summarized as follows:

1.   ATmega32 has 32 KB programmable flash memory, static RAM of 2 KB and EEPROM of 1 KB. The endurance cycle of flash memory and EEPROM is 10,000 and 100,000, respectively.

 

	ATmega32	ATmega16
RAM	2 KB	1 KB
Flash	32 KB	16 KB
EEPROM	1 KB	512 bytes

 

2.    The Bootloader area, the NRWW section starts at word 0x3800 in ATmega32 while in ATmega16 it starts at 0x1C00.

3.    ATmega32 has a different interrupt table, the table given below shows the difference. More details can be obtained from the respective datasheets.

 

Vector #	ATmega32	ATmega16
1	Reset	Reset
2	INT0	INT0
3	INT1	INT1
4	INT2	Timer2 COMP
5	Timer2 COMP	Timer2 OVF
6	Timer2 OVF	Timer1 CAPT
7	Timer1 CAPT	Timer1 COMPA
8	Timer1 COMPA	Timer1 COMPB
9	Timer1 COMPB	Timer1 OVF
10	Timer1 OVF	Timer0 OVF
11	Timer0 COMP	SPI, STC
12	Timer0 OVF	USART, RXC
13	SPI, STC	USART, UDRE
14	USART, RXC	USART, TXC
15	USART, UDRE	ADC
16	USART, TXC	EE_RDY
17	ADC	ANA_COMP
18	EE_RDY	TWI
19	ANA_COMP	INT2
20	TWI	Timer0 COMP
21	SPM_RDY	SPM_RDY

 

4.      In MCUCR register, the SM2 and SE bits are swapped, i.e., the SM2 bit is bit7 and SE bit is bit6 in MCUCR register in ATmega32.

Pin Diagram :

 

Pin Description :

Pin No.	Pin name	Description	Alternate Function
1	(XCK/T0) PB0	I/O PORTB, Pin 0	T0: Timer0 External Counter Input. XCK : USART External Clock I/O
2	(T1) PB1	I/O PORTB, Pin 1	T1:Timer1 External Counter Input
3	(INT2/AIN0) PB2	I/O PORTB, Pin 2	AIN0: Analog Comparator Positive I/P INT2: External Interrupt 2 Input
4	(OC0/AIN1) PB3	I/O PORTB, Pin 3	AIN1: Analog Comparator Negative I/P OC0 : Timer0 Output Compare Match Output
5	(SS) PB4	I/O PORTB, Pin 4	In System Programmer (ISP) Serial Peripheral Interface (SPI)
6	(MOSI) PB5	I/O PORTB, Pin 5
7	(MISO) PB6	I/O PORTB, Pin 6
8	(SCK) PB7	I/O PORTB, Pin 7
9	RESET	Reset Pin, Active Low Reset
10	Vcc	Vcc = +5V
11	GND	GROUND
12	XTAL2	Output to Inverting Oscillator Amplifier
13	XTAL1	Input to Inverting Oscillator Amplifier
14	(RXD) PD0	I/O PORTD, Pin 0	USART Serial Communication Interface
15	(TXD) PD1	I/O PORTD, Pin 1
16	(INT0) PD2	I/O PORTD, Pin 2	External Interrupt INT0
17	(INT1) PD3	I/O PORTD, Pin 3	External Interrupt INT1
18	(OC1B) PD4	I/O PORTD, Pin 4	PWM Channel Outputs
19	(OC1A) PD5	I/O PORTD, Pin 5
20	(ICP) PD6	I/O PORTD, Pin 6	Timer/Counter1 Input Capture Pin
21	PD7 (OC2)	I/O PORTD, Pin 7	Timer/Counter2 Output Compare Match Output
22	PC0 (SCL)	I/O PORTC, Pin 0	TWI Interface
23	PC1 (SDA)	I/O PORTC, Pin 1
24	PC2 (TCK)	I/O PORTC, Pin 2	JTAG Interface
25	PC3 (TMS)	I/O PORTC, Pin 3
26	PC4 (TDO)	I/O PORTC, Pin 4
27	PC5 (TDI)	I/O PORTC, Pin 5
28	PC6 (TOSC1)	I/O PORTC, Pin 6	Timer Oscillator Pin 1
29	PC7 (TOSC2)	I/O PORTC, Pin 7	Timer Oscillator Pin 2
30	AVcc	Voltage Supply = Vcc for ADC
31	GND	GROUND
32	AREF	Analog Reference Pin for ADC
33	PA7 (ADC7)	I/O PORTA, Pin 7	ADC Channel 7
34	PA6 (ADC6)	I/O PORTA, Pin 6	ADC Channel 6
35	PA5 (ADC5)	I/O PORTA, Pin 5	ADC Channel 5
36	PA4 (ADC4)	I/O PORTA, Pin 4	ADC Channel 4
37	PA3 (ADC3)	I/O PORTA, Pin 3	ADC Channel 3
38	PA2 (ADC2)	I/O PORTA, Pin 2	ADC Channel 2
39	PA1 (ADC1)	I/O PORTA, Pin 1	ADC Channel 1
40	PA0 (ADC0)	I/O PORTA, Pin 0	ADC Channel 0