15. AC Timing
403
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
1.
Pulse width measured from Vdd Core (2.5V), Vdd I/O (3.3V), and Px_VDDA supplies in specification
2.
Required for PB_CLK, P1_CLK and P2_CLK. This parameter ensures that each PLL locks. If a frequency change is required, a new power-up
sequence must be initiated.
3.
This parameter is a function of the slowest frequency of PB_CLK, P1_CLK, and P2_CLK. The minimum occurs at 100 MHz, the maximum at 25
MHz. After this time, PowerSpan II is synchronized to external buses and able to participate in transactions once externally applied resets are
released.
4.
Assertion of TRST_ is required at power-up to initialize the JTAG controller and configure the Boundary Scan Register for normal system oper-
ation.
5.
The maximum specification ensures correct power-up levels on PB_FAST, P1_M66EN and P2_M66EN and ensures stable system levels on
INT[5:1]_ before the power-up reset sequence completes.
6.
The ratio of largest to smallest clock period for PB_CLK, P1_CLK, P2_CLK must be strictly less than four. For example, if PB_CLK period is 12
ns, the periods of P1_CLK and P2_CLK must be each less than 48 ns.
PCI Clock Timing
t
130
P1_CLK, P2_CLK period
15
40
ns
P1_CLK, P2_CLK frequency
25
66
MHz
t
131
P1_CLK, P2_CLK high time
6
ns
t
132
P1_CLK, P2_CLK low time
6
ns
t
133
P1_CLK, P2_CLK slew rate
2
V/ns
t
134
P1_CLK, P2_CLK cycle to cycle jitter
300
ps
Clock to Clock Relationships
t
140
Clock period ratio
1
< 4
-
6
Table 102: Reset, and Clock Timing Parameters
Timing
Parameter
Description
CE/IE
Units
Note
Min
Max