Datasheet

206
2586D–AVR–02/06
ATtiny25/45/85
5. EEPROM Write may fail with V
CC
below 2.0 volts
When V
CC
is below 2.0 volts, EEPROM write may fail.
Problem Fix/Work around
Do not write the EEPROM when V
CC
is below 2.0 volts
30.2.2 Rev B and C
•
PLL not locking
• EEPROM read from application code does not work in Lock Bit Mode 3
• EEPROM write may fail with V
CC
below 2.0 volts
• Timer Counter 1 PWM output generation on OC1B- XOC1B does not work correctly
1. PLL not locking
When at frequencies below 6.0 MHz, the PLL will not lock
Problem fix / Workaround
When using the PLL, run at 6.0 MHz or higher.
2. EEPROM read from application code does not work in Lock Bit Mode 3
When the Memory Lock Bits LB2 and LB1 are programmed to mode 3, EEPROM read does
not work from the application code.
Problem Fix/Work around
Do not set Lock Bit Protection Mode 3 when the application code needs to read from
EEPROM.
3. EEPROM Write may fail with V
CC
below 2.0 volts
When V
CC
is below 2.0 volts, EEPROM write may fail.
Problem Fix/Work around
Do not write the EEPROM when V
CC
is below 2.0 volts
4. Timer Counter 1 PWM output generation on OC1B – XOC1B does not work correctly
Timer Counter1 PWM output OC1B-XOC1B does not work correctly. Only in the case when
the control bits, COM1B1 and COM1B0 are in the same mode as COM1A1 and COM1A0,
respectively, the OC1B-XOC1B output works correctly.
Problem Fix/Work around
The only workaround is to use same control setting on COM1B(1:0) and COM1B(1:0) con-
trol bits, see table 14-4 inthe data sheet. The problem has been fixed for Tiny45 rev D.