ATTINY13_08 Datasheet, PDF (166/176 Pages) ATMEL Corporation – 8-bit Microcontroller with 1K Bytes In-System Programmable Flash

24. Errata
The revision letter in this section refers to the revision of the ATtiny13 device.
24.1 ATtiny13 Rev. D
• EEPROM can not be written below 1.9 Volt
1. EEPROM can not be written below 1.9 Volt
Writing the EEPROM at V_CC below 1.9 volts might fail.
Problem Fix/Workaround
Do not write the EEPROM when V_CC is below 1.9 volts.
24.2 ATtiny13 Rev. C
Revision C has not been sampled.
24.3
ATtiny13 Rev. B
• Wrong values read after Erase Only operation
• High Voltage Serial Programming Flash, EEPROM, Fuse and Lock Bits may fail
• Device may lock for further programming
• debugWIRE communication not blocked by lock-bits
• Watchdog Timer Interrupt disabled
• EEPROM can not be written below 1.9 Volt
24.3.1
Wrong values read after Erase Only operation
At supply voltages below 2.7 V, an EEPROM location that is erased by the Erase Only oper-
ation may read as programmed (0x00).
Problem Fix/Workaround
If it is necessary to read an EEPROM location after Erase Only, use an Atomic Write opera-
tion with 0xFF as data in order to erase a location. In any case, the Write Only operation can
be used as intended. Thus no special considerations are needed as long as the erased loca-
tion is not read before it is programmed.
24.3.2
High Voltage Serial Programming Flash, EEPROM, Fuse and Lock Bits may fail
Writing to any of these locations and bits may in some occasions fail.
Problem Fix/Workaround
After a writing has been initiated, always observe the RDY/BSY signal. If the writing should
fail, rewrite until the RDY/BSY verifies a correct writing. This will be fixed in revision D.
24.3.3
Device may lock for further programming
Special combinations of fuse bits will lock the device for further programming effectively
turning it into an OTP device. The following combinations of settings/fuse bits will cause this
effect:
– 128 kHz internal oscillator (CKSEL[1..0] = 11), shortest start-up time
(SUT[1..0] = 00), Debugwire enabled (DWEN = 0) or Reset disabled RSTDISBL = 0.
– 9.6 MHz internal oscillator (CKSEL[1..0] = 10), shortest start-up time
(SUT[1..0] = 00), Debugwire enabled (DWEN = 0) or Reset disabled RSTDISBL = 0.
166 ATtiny13
2535I–AVR–05/08