419
7679H–CAN–08/08
AT90CAN32/64/128
4.
Reset of Timer-2 flags in asynchronous mode
In asynchronous mode, a writing in any register of the TIMER-2 (TCCR2A, TCNT2 &
OCR2A) automatically clears TOV2 and OCF2A flags in TFIR register.
Problem fix / workaround
– TOV2: Do not write in Timer-2 registers if TCNT2 is equal to 0xFF, 0x00 or 0x01.
– OCF2A: Do not write in Timer-2 registers if TCNT2 and OCR2A differ from -1, 0 or 1.
3.
Miss-functioning when code stack is in XRAM
If the stack pointer (SP) targets the XRAM and if the execution of an instruction is split to
serve a rising interrupt, the last operation of this instruction, executed after pushing out the
return address from XRAM, may be disturbed providing wrong data to the system.
Example: - the “OUT” instruction can be executed twice
- the “MOV” instruction can update a register with un-predictable data.
Problem fix / workaround
Map the code stack in internal SRAM.
2. Extra consumption in power reduction modes
When AVCC is selected as voltage reference for ADC (REF[1,0]=0,1), an extra consumption
close to 30 µA (5.0V/25°C) appears in power reduction modes.
Problem fix / workaround
Switch from AVCC to AREF pin (REF[1,0]=0,0) before enabling one of the power reduction
modes.
1.
Power supply current in Power-down mode
The power supply current in Power-down mode of AT90CAN128
parts with lot number
before A04900 is:
T
A
= - 40°C to + 85°C
Symbol
Parameter
Condition
Min.
Typ.
Max.
Max.
I
CC
Power Supply Current
Power-down Mode
WDT enabled, V
CC
= 5 V
150
µA
WDT disabled, V
CC
= 5 V
120
µA
WDT enabled, V
CC
= 3 V
50
µA
WDT disabled, V
CC
= 3 V
40
µA
Содержание AVR AT90CAN128
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