ATMEGA128-16AU Atmel, ATMEGA128-16AU Datasheet - Page 52

• Manufacturer Part Number: ATMEGA128-16AU
• Description: IC AVR MCU 128K 16MHZ 5V 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA128-16AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: 2-Wire, JTAG, SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 53
• Number Of Timers: 4
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AVR MEGA
• No. Of I/o's: 53
• Eeprom Memory Size: 4096Byte
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEMATSTK501 - ADAPTER KIT FOR 64PIN AVR MCUATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Internal Voltage
Reference
Voltage Reference Enable
Signals and Start-up Time
Watchdog Timer
52
ATmega128
ATmega128 features an internal bandgap reference. This reference is used for Brown-
out Detection, and it can be used as an input to the Analog Comparator or the ADC. The
2.56V reference to the ADC is generated from the internal bandgap reference.
The voltage reference has a start-up time that may influence the way it should be used.
The start-up time is given in Table 20. To save power, the reference is not always turned
on. The reference is on during the following situations:
1. When the BOD is enabled (by programming the BODEN fuse).
2. When the bandgap reference is connected to the Analog Comparator (by setting
3. When the ADC is enabled.
Thus, when the BOD is not enabled, after setting the ACBG bit or enabling the ADC, the
user must always allow the reference to start up before the output from the Analog Com-
parator or ADC is used. To reduce power consumption in Power-down mode, the user
can avoid the three conditions above to ensure that the reference is turned off before
entering Power-down mode.
Table 20. Internal Voltage Reference Characteristics
The Watchdog Timer is clocked from a separate On-chip Oscillator which runs at 1 Mhz.
This is the typical value at V
V
can be adjusted as shown in Table 22 on page 54. The WDR – Watchdog Reset –
instruction resets the Watchdog Timer. The Watchdog Timer is also reset when it is dis-
abled and when a Chip Reset occurs. Eight different clock cycle periods can be selected
to determine the reset period. If the reset period expires without another Watchdog
Reset, the ATmega128 resets and executes from the Reset Vector. For timing details on
the Watchdog Reset, refer to page 51.
To prevent unintentional disabling of the Watchdog or unintentional change of time-out
period, 3 different safety levels are selected by the Fuses M103C and WDTON as
shown in Table 21. Safety level 0 corresponds to the setting in ATmega103. There is no
restriction on enabling the WDT in any of the safety levels. Refer to “Timed Sequences
for Changing the Configuration of the Watchdog Timer” on page 55 for details.
CC
Symbol
the ACBG bit in ACSR).
V
t
I
levels. By controlling the Watchdog Timer prescaler, the Watchdog Reset interval
BG
BG
BG
Parameter
Bandgap reference voltage
Bandgap reference start-up time
Bandgap reference current consumption
CC
= 5V. See characterization data for typical values at other
1.15
Min
1.23
Typ
40
10
Max
1.40
70
2467M–AVR–11/04
Units
µA
µs
V