351
2570N–AVR–05/11
ATmega325/3250/645/6450
34.2.3
ATmega3250 Rev. A
Interrupts may be lost when writing the timer registers in the asynchronous timer
1.
Interrupts may be lost when writing the timer registers in the asynchronous timer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/ Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
34.3
Errata ATmega645
The revision letter in this section refers to the revision of the ATmega645 device.
34.3.1
ATmega645 Rev. A
Interrupts may be lost when writing the timer registers in the asynchronous timer
1.
Interrupts may be lost when writing the timer registers in the asynchronous timer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/ Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
34.4
Errata ATmega6450
The revision letter in this section refers to the revision of the ATmega6450 device.
34.4.1
ATmega6450 Rev. A
Interrupts may be lost when writing the timer registers in the asynchronous timer
1.
Interrupts may be lost when writing the timer registers in the asynchronous timer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/ Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).