ATMEGA103L_14 Datasheet, PDF (1/4 Pages) ATMEL Corporation – Wake-up from Power Save Executes Instructions before Interrupt

Errata
• Wake-up from Power Save Executes Instructions before Interrupt
• SPI can Send Wrong Byte
• Wrong Clearing of EXTRF in MCUSR
• Reset during EEPROM Write
• SPI Interrupt Flag can be Undefined after Reset
• Serial Programming at Voltages below 3.4V
• Skip Instruction with Interrupts
• Signature Bytes
• Read Back Value during EEPROM Polling
• MISO Active during In-System Programming
• The ADC has no Free-running Mode
• UART Loses Synchronization if RXD Line is Low when UART Receive is Disabled
12. Wake-up from Power Save Executes Instructions before Interrupt
When waking up from power save, some instructions are executed before the
interrupt is called. If the device is woken up by an external interrupt, 2 instruction
cycles are executed. If it is woken up by the asynchronous timer, 3 instructions
are executed before the interrupt.
Problem Fix/Workaround
Make sure that the first two or three instructions following sleep are not dependent
on the executed interrupt.
11. The SPI can Send Wrong Byte
If the SPI is in Master mode, it will restart the old transfer if new data is written on
the same clock edge as the previous transfer is finished.
Problem Fix/Workaround
When writing to the SPI, first wait until it is ready, then write the byte to transmit.
10. Wrong Clearing of EXTRF in MCUSR
The EXTRF flag in MCUSR will be cleared when clearing the PORF-flag. The flag
does not get cleared by writing a “0” to it.
Problem Fix/Workaround
Finish the test of both flags before clearing any of them. Clear both flags simulta-
neously by writing “0” to both PORF and EXTRF in MCUCR.
9. Reset during EEPROM Write
If reset is activated during EEPROM write, the result is not what should be
expected. The EEPROM write cycle completes as normal, but the address regis-
ters are reset to 0. The result is that both the address written and address 0 in the
EEPROM can be corrupted.
Problem Fix/Workaround
Avoid using address 0 for storage, unless you can guarantee that you will not get
a reset during EEPROM write.
8-bit
Microcontroller
with 128K Bytes
In-System
Programmable
Flash
ATmega103L
Rev. F/G
Errata Sheet
Rev. 1197D–12/99
1