ATMEGA103-6AI Atmel, ATMEGA103-6AI Datasheet - Page 29

IC MCU 128K 6MHZ A/D IT 64TQFP

ATMEGA103-6AI

Manufacturer Part Number
ATMEGA103-6AI
Description
IC MCU 128K 6MHZ A/D IT 64TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets

Specifications of ATMEGA103-6AI

Core Processor
AVR
Core Size
8-Bit
Speed
6MHz
Connectivity
SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
32
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 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
64-TQFP, 64-VQFP
For Use With
ATSTK501 - ADAPTER KIT FOR 64PIN AVR MCU
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Watchdog Reset
MCU Status Register –
MCUSR
0945I–AVR–02/07
When the Watchdog times out, it will generate a short reset pulse of 1 XTAL cycle dura-
tion. On the falling edge of this pulse, the delay timer starts counting the Time-out period
t
. Refer to page 55 for details on operation of the Watchdog.
TOUT
Figure 27. Watchdog Reset during Operation
VCC
RESET
1 XTAL Cycle
WDT
TIME-OUT
RESET
TIME-OUT
INTERNAL
RESET
The MCU Status Register provides information on which reset source caused an MCU
reset.
Bit
7
6
5
$34 ($54)
Read/Write
R
R
R
Initial Value
0
0
0
• Bits 7..2 – Res: Reserved Bits
These bits are reserved bits in the ATmega103(L) and always read as zero.
• Bit 1 – EXTRF: External Reset Flag
After a Power-on Reset, this bit is undefined (X). It will be set by an external reset. A
Watchdog reset will leave this bit unchanged.
• Bit 0 – PORF: Power-on Reset Flag
This bit is set by a Power-on Reset. A Watchdog Reset or an External Reset will leave
this bit unchanged.
To summarize, Table 7 shows the value of these two bits after the three modes of reset:
Table 7. PORF and EXTRF Values after Reset
Reset Source
Power-on Reset
External Reset
Watchdog Reset
To make use of these bits to identify a reset condition, the user software should clear
both the PORF and EXTRF bits as early as possible in the program. Checking the
PORF and EXTRF values is done before the bits are cleared. If the bit is cleared before
ATmega103(L)
t
TOUT
4
3
2
1
EXTRF
R
R
R
R/W
0
0
0
See bit description
EXTRF
undefined
1
unchanged
0
PORF
MCUSR
R/W
PORF
1
unchanged
unchanged
29

Related parts for ATMEGA103-6AI