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DS3171/DS3172/DS3173/DS3174
233
18.8 JTAG Interface AC Characteristics
All AC timing characteristics are specified with a 50pF capacitive load on JTDO pin and 25pF capacitive load on all
other digital output pins, V
IH
= 2.4V and V
IL
= 0.8. The voltage threshold for all timing measurements is V
DD
/2. The
generic timing definitions shown
, and
interface.
Table 18-13. JTAG Interface Timing
(V
DD
= 3.3V
±
5%, T
j
= -40°C to +125°C.)
SIGNAL
NAME(S)
SYMBOL DESCRIPTION MIN TYP
MAX
UNITS NOTES
JTCLK
f1
Clock Frequency (1/t1)
0
10
MHz
JTCLK
t2
Clock High or Low Period
20
ns
JTCLK t3
Rise/Fall
Times
5
ns
JTMS and JTDI
t5
Hold Time from JTCLK Rising Edge
10
ns
JTMS and JTDI
t6
Setup Time to JTCLK Rising Edge
10
ns
JTDO
t7
Delay from JTCLK Falling Edge
0
20
ns
JTDO
t8
Delay out of HiZ from JTCLK Falling Edge
0
20
ns
JTDO
t9
Delay to HiZ from JTCLK Falling Edge
0
20
ns
Any digital output
t7
Delay from JTCLK Falling Edge
0
20
ns
1
Any digital output
t7
Delay from JTCLK Rising Edge
0
20
ns
2
Any digital output
t8
Delay out of HiZ from JTCLK Falling Edge
0
20
ns
1
Any digital output
t9
Delay into HiZ from JTCLK Falling Edge
0
20
ns
1
Any digital output
t8
Delay out of HiZ from JTCLK Rising Edge
0
20
ns
2, 3
Any digital output
t9
Delay into HiZ from JTCLK Rising Edge
0
20
ns
2, 3
Note 1:
Change during Update-DR state.
Note 2:
Change during Update-IR state to or from EXTEST mode.
Note 3:
Change during Update-IR state to or from HIZ mode.