Texas Instruments SM320C6455-EP, Руководство по данным

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7.7.4 PLL1 Controller Input and Output Clock Electrical Data/Timing
CLKIN1
2
3
4
4
5
1
SYSCLK4
3
4
4
2
SM320C6455-EP
FIXED-POINT DIGITAL SIGNAL PROCESSOR
SPRS462B – SEPTEMBER 2007 – REVISED JANUARY 2008
Table 7-29. Timing Requirements for CLKIN1 Devices
(1) (2) (3)
(see Figure 7-21 )
-720
-850
A-1000/-1000
-1200
NO. UNIT
PLL MODES
x1 (Bypass), x15,
x20, x25, x30, x32
MIN MAX
1 t
c(CLKIN1)
Cycle time, CLKIN1
(4)
15 30.3 ns
2 t
w(CLKIN1H)
Pulse duration, CLKIN1 high 0.4C ns
3 t
w(CLKIN1L)
Pulse duration, CLKIN1 low 0.4C ns
4 t
t(CLKIN1)
Transition time, CLKIN1 1.2 ns
5 t
J(CLKIN1)
Period jitter (peak-to-peak), CLKIN1 100 ps
(1) The reference points for the rise and fall transitions are measured at 3.3 V V
IL
MAX and V
IH
MIN.
(2) For more details on the PLL multiplier factors (x1 [BYPASS], x 15, x20, x25, x30, x32), see Section 7.7.1.2 , PLL1 Controller Operating
Modes .
(3) C = CLKIN1 cycle time in ns. For example, when CLKIN1 frequency is 50 MHz, use C = 20 ns.
(4) The PLL1 multiplier factors (x1 [BYPASS], x 15, x20, x25, x30, x32) further limit the MIN and MAX values for t
c(CLKIN1)
. For more
detailed information on these limitations, see Section 7.7.1.1 , Internal Clocks and Maximum Operating Frequencies .
Figure 7-21. CLKIN1 Timing
Table 7-30. Switching Characteristics Over Recommended Operating Conditions for SYSCLK4
[CPU/8 - CPU/12]
(1) (2)
(see Figure 7-22 )
-720
-850
A-1000/-1000
NO. PARAMETER UNIT
-1200
MIN MAX
2 t
w(CKO3H)
Pulse duration, SYSCLK4 high 4P – 0.7 6P + 0.7 ns
3 t
w(CKO3L)
Pulse duration, SYSCLK4 low 4P – 0.7 6P + 0.7 ns
4 t
t(CKO3)
Transition time, SYSCLK4 1 ns
(1) The reference points for the rise and fall transitions are measured at 3.3 V V
OL
MAX and V
OH
MIN.
(2) P = 1/CPU clock frequency in nanoseconds (ns)
Figure 7-22. SYSCLK4 Timing
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