Datasheet

XDS560 Emulator Cable Pod Signal Timing
3-11
Target Design Considerations for Using the XDS560 Emulation Pod
t
pdĂ
ǒ
TCK_RET*TDO
Ǔ
Ă +Ă
ƪ
t
d
(
TTDO
)
) t
su
(
TDOmin
)
ƫ
t
ǒ
TCKfactor
Ǔ
+Ă
[
15Ăns ) 2.5Ăns
]
0.4
+Ă 43.75ĂnsĂ
(
22.9ĂMHz
)
In this case, the TCK_RET-to-TDO path is the limiting factor.
Equation 3−2. Key Timing Path Case 2
Case 2: Single/multiprocessor, TMS/TDI/TCK buffered input, TDO buffered
output,
TMS/TDI timed from TCK_RET high.
t
pdĂ
ǒ
TCK_RET*TMSńTDI
Ǔ
Ă +Ă t
d
(
TMSmax
)
) t
su
(
TTMS
)
) t
ǒ
bufskew
Ǔ
+Ă
[
31Ăns ) 10Ăns ) 1.35Ăns
]
+Ă 42.35ĂnsĂ
(
23.6ĂMHz
)
t
pdĂ
ǒ
TCK_RET*TDO
Ǔ
Ă +Ă
ƪ
t
d
(
TTDO
)
) t
su
(
TDOmin
)
) t
d
ǒ
bufmax
Ǔ
ƫ
t
ǒ
TCKfactor
Ǔ
+Ă
[
15Ăns ) 2.5Ăns ) 10Ăns
]
0.4
+Ă 68.75ĂnsĂ
(
14.5ĂMHz
)
In this case, the TCK_RET-to-TDO path is the limiting factor.