Analog Devices ADSP-21020 manual Timing Requirement1, FLAG3-0INSetup before Clkin High 19 + 5DT/16

ADSP-21020

Flags

									K/B/T Grade	K/B/T Grade	B/T Grade	K Grade
									20 MHz	25 MHz	30 MHz	33.3 MHz	Frequency Dependency*
Parameter									Min Max	Min Max	Min Max	Min Max	Min	Max	Unit
Timing Requirement:1
tSFI	FLAG3-0INSetup before CLKIN High								19	16	14	13	19 + 5DT/16		ns
tHFI	FLAG3-0INHold after CLKIN High								0	0	0	0			ns
tDWRFI FLAG3-0INDelay from			xRD		,		xWR	Low	12	8	5	3		12 + 7DT/16	ns
tHFIWR FLAG3-0INHold after		xRD		,		xWR			0	0	0	0			ns
	Deasserted
Switching Characteristic:
tDFO	FLAG3-0OUTDelay from CLKIN High								24	24	24	24			ns
tHFO	FLAG3-0OUTHold after CLKIN High								5	5	5	5			ns
tDFOE	CLKIN High to FLAG3-0OUTEnable								1	1	1	1			ns
tDFOD	CLKIN High to FLAG3-0OUTDisable								24	24	24	24			ns

NOTES

*DT = tCK – 50 ns

1Flag inputs meeting these setup and hold times will affect conditional operations in the next instruction cycle. See the Hardware Configuration chapter of the ADSP-21020 User’s Manual for additional flag servicing information.

x = PM or DM.

CLKIN

	tDFO
tDFO	tDFOD
tDFOE	tHFO

FLAG3-0OUT

CLKIN

tSFI

FLAG OUTPUT

tHFI

FLAG3-0 IN

tDWRFI

xRD, xWR

tHFIWR

FLAG INPUT

Figure 7. Flags

REV. C –15–