15
AT94KAL Series FPSLIC
Rev. 1138G–FPSLI–11/03
The FPGA clocks from the AVR are effected differently in the various sleep modes of the AVR,
see Table 3.
The source clock into the FPGA GCK5 and GCK6 will determine what happens during the var-
ious power-down modes of the AVR.
If the XTAL clock input is used as an FPGA clock (GCK5 or GCK6) in Idle mode, it will still be
running. In Power-down/save mode the XTAL clock input will be off.
If the TOSC clock input is used as an FPGA clock (GCK6) in Idle mode, it will still be running in
Power-save mode but will be off in Power-down mode.
If the Watchdog Timer is used as an FPGA clock (GCK6) and was enabled in the AVR, it will
be running in all sleep modes.
Table 3.
Clock Activity in Various Modes
Mode
Clock Source
GCK5
GCK6
Idle
XTAL
Active
Active
TOSC
Not Available
Active
WDT
Not Available
Active
Power-save
XTAL
Inactive
Inactive
TOSC
Not Available
Active
WDT
Not Available
Active
Power-down
XTAL
Inactive
Inactive
TOSC
Not Available
Inactive
WDT
Not Available
Active