ATmega128L 8-bit Atmel Microcontroller with 128KBytes In-System Programmable Flash

ATMEGA128L is a high-performance, low-power, 8-bit microcontroller from Microchip which is based on AVR RISC architecture. This microcontroller is not that popular among hobbyists and developers but if you are looking for medium power and reasonable price microcontroller from the Microchip AVR series, then this could be a great choice for you.

 

Atmega128L Pin Configuration

ATMEGA328P is a 64 pins chip as shown in the pin diagram above. Many pins of the chip here have more than one function. We will describe the functions of each pin in the below table.

Pin No	Pin Name	Pin Functions	Description and Secondary Functions
1			programming enable pin for the Serial Programming mode
2	PE0	RXD0/(PDI)	PDI/RXD0 (Programming Data Input or UART0 Receive Pin)
3	PE1	TXD0/PDO	PDO/TXD0 (Programming Data Output) or UART0 Transmit Pin
4	PE2	XCK0/AIN0	Analog Comparator Positive Input or USART0 external clock input/output
5	PE3	OC3A/AIN1	Analog Comparator Negative Input or Output Compare and PWM Output A for Timer/Counter3
6	PE4	OC3B/INT4	External Interrupt4 Input or Output Compare and PWM Output B for Timer/Counter3
7	PE5	OC3C/INT5	External Interrupt 5 Input or Output Compare and PWM Output C for Timer/Counter3
8	PE6	T3/INT6	External Interrupt 6 Input or Timer/Counter3 Clock Input
9	PE7	ICP3/INT7	External Interrupt 7 Input or Timer/Counter3 Input Capture Pin
10	PB0		SPI Slave Select input
11	PB1	SCK	SPI Bus Serial Clock
12	PB2	MOSI	SPI Bus Master Output/Slave Input
13	PB3	MISO	SPI Bus Master Input/Slave Output
14	PB4	OC0	Output Compare and PWM Output for Timer/Counter0
15	PB5	OC1A	Output Compare and PWM Output A for Timer/Counter1
16	PB6	OC1B	Output Compare and PWM Output B for Timer/Counter1
17	PB7	OC2/OC1C	Output Compare and PWM Output for Timer/Counter2 or Output Compare and PWM Output C for Timer/Counter1
18	PG3	TOSC2	RTC Oscillator Timer/Counter0
19	PG4	TOSC1/PG4	RTC Oscillator Timer/Counter0
20
21	VCC	VCC	Digital supply voltage
22	GND	GND	Ground
23	XTAL2	XTAL2	XTAL2 (Chip Clock Oscillator pin 2)
24	XTAL1	XTAL1	XTAL1 (Chip Clock Oscillator pin 2)
25	PD0	SCL/I NT0	External Interrupt0 Input or TWI Serial CLock)
26	PD1	SDA/I NT1	External Interrupt1 Input or TWI Serial Data
27	PD2	RXD1/I NT2	External Interrupt2 Input or UART1 Receive Pin
28	PD3	TXD1/I NT3	External Interrupt3 Input or UART1 Transmit Pin
29	PD4	ICP1	Timer/Counter1 Input Capture Pin
30	PD5	XCK1	USART1 External Clock Input/Output
31	PD6	T1	Timer/Counter1 Clock Input
32	PD7	T2	Timer/Counter2 Clock Input
33	PG0		Write strobe to external memory
34	PG1		Read strobe to external memory
35	PC0	A8	Compatibility mode can be used for External Memory Interface
36	PC1	A9	Compatibility mode can be used for External Memory Interface
37	PC2	A10	Compatibility mode can be used for External Memory Interface
38	PC3	A11	Compatibility mode can be used for External Memory Interface
39	PC4	A12	Compatibility mode can be used for External Memory Interface
40	PC5	A13	Compatibility mode can be used for External Memory Interface
41	PC6	A14	Compatibility mode can be used for External Memory Interface
42	PC7	A15	Compatibility mode can be used for External Memory Interface
43	PG2	ALE	ALE is the external data memory Address Latch Enable signal.
44	PA7	AD7	External memory interface address and data bit 7
45	PA6	AD6	External memory interface address and data bit 6
46	PA5	AD5	External memory interface address and data bit 5
47	PA4	AD4	External memory interface address and data bit 4
48	PA3	AD3	External memory interface address and data bit 3
49	PA2	AD2	External memory interface address and data bit 2
50	PA1	AD1	External memory interface address and data bit 1
51	PA0	AD0	External memory interface address and data bit 0
52	VCC	VCC	Digital supply voltage
53	GND	GND	Ground
54	PF7	ADC7/TDI	ADC input channel 7 or JTAG Test Data Input
55	PF6	ADC6/TDO	ADC input channel 6 or JTAG Test Data Output
56	PF5	ADC5/TMS	ADC input channel 5 or JTAG Test Mode Select
57	PF4	ADC4/TCK	ADC input channel 4 or JTAG Test ClocK
58	PF3	ADC3	ADC input channel 3
59	PF2	ADC2	ADC input channel 2
60	PF1	ADC1	ADC input channel 1
61	PF0	ADC0	ADC input channel 0
62	AREF	AREF	AREF is the analog reference pin for the A/D Converter
63	GND	GND	Ground
64	AVCC	AVCC	AVCC is the supply voltage pin for Port F and the A/D Converter. it should be connected to VCC through a low-pass filter.

 

Note: Check the ATmega128L Datasheet attached at the bottom of the page for more information on compatibility mode.

 

Features & Specifications of ATmega128L

• Operating Voltage: 2.7 - 5.5V ATmega128L
• Frequency Grade: 0 - 8MHz ATmega128L
• High Endurance Non-volatile Memory segments
• 128Kbytes of In-System Self-programmable Flash program memory
• 4Kbytes EEPROM
• 4Kbytes Internal SRAM
• Write/Erase cycles: 10,000 Flash/100,000 EEPROM
• Two 8-bit PWM Channels
• 6 PWM Channels with Programmable Resolution from 2 to 16 Bits
• 8-channel, 10-bit ADC
• Master/Slave SPI Serial Interface
• Two Expanded 16-bit Timer/Counters with Separate Prescaler, Compare Mode, and Capture Mode
• Programmable Watchdog Timer with On-chip Oscillator
• On-chip Analog Comparator
• Two 8-bit Timer/Counters with Separate Prescaler
• Dual Programmable Serial USARTs
• Internal Calibrated RC Oscillator
• Software Selectable Clock Frequency
• JTAG (IEEE std. 1149.1 Compliant) Interface with Boundary Scan, on-chip debugging
• Optional Boot Code Section with Independent Lock Bits
• In-System Programming by On-chip Boot Program
• Data retention: 20 years at 85°C/100 years at 25°C

 

Similar Microcontrollers alike ATmega128L

ATmega8, ATmega88, ATmega8L, ATmega328L

 

How to Use ATMEGA128L

ATmega128L is a microcontroller that needs to be programmed otherwise it will do nothing like every other microcontroller out there. Without a program, this IC will do nothing but consume current to run internal functions. There are various ways to program an ATmega128L microcontroller, the most popular way is to use a USBasp Programmer with AVRDude as a programming interface, you can build and compile your program in order to get a HEX file. When you get your HEX file you can dump the HEX on this IC with the help of the AVRDUDE Program. Another way to program this device is to use the Arduino as ISP Programmer, if you have an Arduino in hand you can search the web for numerous examples of how to do so. The next option is for those who do not have an Arduino or an USBasp Programmer, this process is called is Parallel Programming, you have to use the Parallel Port which is only available in older Desktop PCs, if you do not have the port, you can always purchase a PCI Parallel port converter for cheap.

 

Where to Use ATMEGA128L

As we have said earlier the Atmega128L is not that popular in comparison to Arduino, although there is an old version of Arduino that uses the ATmega128L as its main Controller. As the price of this controller is less than the ATmega328P along with a program memory of 32 Kbytes. This microcontroller can be used in many battery-powered applications with a watchdog timer to reset under error. It can be used on systems with minimal human interference and also has an advanced multi-mode PWM output that can be used for many different applications. The block diagram of the ATmega128L is shown below-

 

Applications

There are hundreds of applications for ATMEGA328P:

• Industrial control systems.
• SMPS and Power Regulation systems.
• Digital data processing.
• Analog signal measuring and manipulations.
• Embedded systems like coffee machines, vending machines.
• Motor control systems.
• Display units.
• Peripheral Interface system.

 

2D Model and Dimensions

Below is the 2D model of the IC along with its dimensions in inches(millimeters). The following information can be used to design the custom footprints and be used for PCB designing and CAD modeling.