ADSP-2181
P aram eter
Min
Max
Unit
Inter r upts and Flag
Timing Requirements:
tIFS
tIFH
IRQx, FI, or PFx Setup before CLKOUT Low1, 2, 3, 4
IRQx, FI, or PFx Hold after CLKOUT High1, 2, 3, 4
0.25tCK + 15
0.25tCK
ns
ns
Switching Characteristics:
tFOH
Flag Output Hold after CLKOUT Low5
tFOD
Flag Output Delay from CLKOUT Low5
0.5tCK – 7
ns
ns
0.5tCK + 5
NOT ES
1If IRQx and FI inputs meet tIFS and tIFH setup/hold requirements, they will be recognized during the current clock cycle; otherwise the signals will be recognized on
the following cycle. (Refer to “Interrupt Controller Operation” in the Program Control chapter of the User’s Manual for further information on interrupt servicing.)
2Edge-sensitive interrupts require pulsewidths greater than 10 ns; level-sensitive interrupts must be held low until serviced.
3IRQx = IRQ0, IRQ1, IRQ2, IRQL0, IRQL1, IRQE.
4PFx = PF0, PF1, PF2, PF3, PF4, PF5, PF6, PF7.
5Flag outputs = PFx, FL0, FL1, FL2, Flag_out4.
tFOD
CLKOUT
tFOH
FLAG
OUTPUTS
tIFH
IRQx
FI
PFx
tIFS
Figure 9. Interrupts and Flags
REV. D
–15–
ADI [ ADI ]
