7 clock requirements and characteristics – Texas Instruments TMS320F2802 User Manual
Page 105
SPRS230N – OCTOBER 2003 – REVISED MAY 2012
6.7
Clock Requirements and Characteristics
Table 6-8. Input Clock Frequency
PARAMETER
MIN
TYP
MAX
UNIT
Resonator (X1/X2)
20
35
Crystal (X1/X2)
20
35
f
x
Input clock frequency
MHz
100-MHz device
4
100
External oscillator/clock
source (XCLKIN or X1 pin)
60-MHz device
4
60
f
l
Limp mode SYSCLKOUT frequency range (with /2 enabled)
1–5
MHz
Table 6-9. XCLKIN
(1)
Timing Requirements - PLL Enabled
NO.
MIN
MAX
UNIT
C8
t
c(CI)
Cycle time, XCLKIN
33.3
200
ns
C9
t
f(CI)
Fall time, XCLKIN
6
ns
C10
t
r(CI)
Rise time, XCLKIN
6
ns
C11
t
w(CIL)
Pulse duration, XCLKIN low as a percentage of t
c(OSCCLK)
45
55
%
C12
t
w(CIH)
Pulse duration, XCLKIN high as a percentage of t
c(OSCCLK)
45
55
%
(1)
This applies to the X1 pin also.
Table 6-10. XCLKIN
(1)
Timing Requirements - PLL Disabled
NO.
MIN
MAX
UNIT
C8
t
c(CI)
Cycle time, XCLKIN
100-MHz device
10
250
ns
60-MHz device
16.67
250
C9
t
f(CI)
Fall time, XCLKIN
Up to 20 MHz
6
ns
20 MHz to 100 MHz
2
ns
C10
t
r(CI)
Rise time, XCLKIN
Up to 20 MHz
6
ns
20 MHz to 100 MHz
2
ns
C11
t
w(CIL)
Pulse duration, XCLKIN low as a percentage of t
c(OSCCLK)
45
55
%
C12
t
w(CIH)
Pulse duration, XCLKIN high as a percentage of t
c(OSCCLK)
45
55
%
(1)
This applies to the X1 pin also.
The possible configuration modes are shown in
.
Table 6-11. XCLKOUT Switching Characteristics (PLL Bypassed or Enabled)
(1) (2)
NO.
PARAMETER
MIN
TYP
MAX
UNIT
100-MHz device
10
C1
t
c(XCO)
Cycle time, XCLKOUT
ns
60-MHz device
16.67
C3
t
f(XCO)
Fall time, XCLKOUT
2
ns
C4
t
r(XCO)
Rise time, XCLKOUT
2
ns
C5
t
w(XCOL)
Pulse duration, XCLKOUT low
H – 2
H + 2
ns
C6
t
w(XCOH)
Pulse duration, XCLKOUT high
H – 2
H + 2
ns
t
p
PLL lock time
131072t
c(OSCCLK)
(3)
cycles
(1)
A load of 40 pF is assumed for these parameters.
(2)
H = 0.5t
c(XCO)
(3)
OSCCLK is either the output of the on-chip oscillator or the output from an external oscillator.
Copyright © 2003–2012, Texas Instruments Incorporated
Electrical Specifications
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