ATTINY25-20SU Atmel, ATTINY25-20SU Datasheet - Page 19
![IC AVR MCU 2K 20MHZ 8-SOIC](/photos/6/50/65032/453-8-soic_sml.jpg)
ATTINY25-20SU
Manufacturer Part Number
ATTINY25-20SU
Description
IC AVR MCU 2K 20MHZ 8-SOIC
Manufacturer
Atmel
Series
AVR® ATtinyr
Specifications of ATTINY25-20SU
Core Processor
AVR
Core Size
8-Bit
Speed
20MHz
Connectivity
USI
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
6
Program Memory Size
2KB (1K x 16)
Program Memory Type
FLASH
Eeprom Size
128 x 8
Ram Size
128 x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Data Converters
A/D 4x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
Processor Series
ATTINY2x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
128 B
Interface Type
USI
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
6
Number Of Timers
2
Operating Supply Voltage
2.7 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
4-ch x 10-bit
For Use With
ATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIPATAVRBC100 - REF DESIGN KIT BATTERY CHARGER770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATTINY25-20SU
Manufacturer:
ATMEL
Quantity:
3 999
Company:
Part Number:
ATTINY25-20SU
Manufacturer:
Atmel
Quantity:
27 597
Part Number:
ATTINY25-20SU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
5.3.6
2586M–AVR–07/10
Preventing EEPROM Corruption
The next code examples show assembly and C functions for reading the EEPROM. The exam-
ples assume that interrupts are controlled so that no interrupts will occur during execution of
these functions.
During periods of low V
too low for the CPU and the EEPROM to operate properly. These issues are the same as for
board level systems using EEPROM, and the same design solutions should be applied.
An EEPROM data corruption can be caused by two situations when the voltage is too low. First,
a regular write sequence to the EEPROM requires a minimum voltage to operate correctly. Sec-
ondly, the CPU itself can execute instructions incorrectly, if the supply voltage is too low.
EEPROM data corruption can easily be avoided by following this design recommendation:
Keep the AVR RESET active (low) during periods of insufficient power supply voltage. This can
be done by enabling the internal Brown-out Detector (BOD). If the detection level of the internal
BOD does not match the needed detection level, an external low V
be used. If a reset occurs while a write operation is in progress, the write operation will be com-
pleted provided that the power supply voltage is sufficient.
Assembly Code Example
C Code Example
EEPROM_read:
unsigned char EEPROM_read(unsigned char ucAddress)
{
}
; Wait for completion of previous write
sbic EECR,EEPE
rjmp EEPROM_read
; Set up address (r18:r17) in address register
out EEARH, r18
out EEARL, r17
; Start eeprom read by writing EERE
sbi EECR,EERE
; Read data from data register
in
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEPE))
/* Set up address register */
EEAR = ucAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from data register */
return EEDR;
;
r16,EEDR
CC
, the EEPROM data can be corrupted because the supply voltage is
CC
reset protection circuit can
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