Network Router User Manual

XCLKOUT
(/1 Mode)
XHOLD
XR/W,
XZCS0AND1
,
XZCS2
,
XZCS6AND7
XD[15:0] Valid
XHOLDA
t
d(HL-Hiz)
t
d(HH-HAH)
High-Impedance
XA[18:0]
Valid
Valid
High-Impedance
t
d(HH-BV)
t
d(HL-HAL)
See Note A
See Note B
SM320F2812-HT
SGUS062A–JUNE 2009 –REVISED APRIL 2010 www.ti.com
6.28 XHOLD/XHOLDA Timing
Table 6-44. XHOLD/XHOLDA Timing Requirements (XCLKOUT = XTIMCLK)
(1) (2) (3)
MIN MAX UNIT
t
d(HL–HiZ)
Delay time, XHOLD low to Hi–Z on all Address, Data, and Control 4t
c(XTIM)
ns
t
d(HL–HAL)
Delay time, XHOLD low to XHOLDA low 5t
c(XTIM)
ns
t
d(HH–HAH)
Delay time, XHOLD high to XHOLDA high 3t
c(XTIM)
ns
t
d(HH–BV)
Delay time, XHOLD high to Bus valid 4t
c(XTIM)
ns
(1) When a low signal is detected on XHOLD, all pending XINTF accesses are completed before the bus is placed in a high-impedance
state.
(2) The state of XHOLD is latched on the rising edge of XTIMCLK.
(3) Not production tested.
A. All pending XINTF accesses are completed.
B. Normal XINTF operation resumes.
Figure 6-35. External Interface Hold Waveform
132 Electrical Specifications Copyright © 2009–2010, Texas Instruments Incorporated
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