LM3S6753 Datasheet, PDF (580/625 Pages) Texas Instruments – Stellaris LM3S6753 Microcontroller

Electrical Characteristics
Figure 23-1. Load Conditions
pin
C_L = 50 pF
GND
23.2.2
Clocks
Table 23-8. Phase Locked Loop (PLL) Characteristics
Parameter Parameter Name
Min
Nom
Max
Unit
f_{ref_crystal}
f_{ref_ext}
f_pll
Crystal reference^a
External clock reference^a
PLL frequency^b
3.579545
-
3.579545
-
-
400
8.192
8.192
-
MHz
MHz
MHz
T_READY
PLL lock time
-
-
0.5
ms
a. The exact value is determined by the crystal value programmed into the XTAL field of the Run-Mode Clock Configuration
(RCC) register.
b. PLL frequency is automatically calculated by the hardware based on the XTAL field of the RCC register.
Table 23-9 on page 580 shows the actual frequency of the PLL based on the crystal frequency used
(defined by the XTAL field in the RCC register).
Table 23-9. Actual PLL Frequency
XTAL
0x4
0x5
0x6
0x7
0x8
0x9
0xA
0xB
0xC
0xD
0xE
0xF
Crystal Frequency (MHz)
3.5795
3.6864
4.0
4.096
4.9152
5.0
5.12
6.0
6.144
7.3728
8.0
8.192
PLL Frequency (MHz)
400.904
398.1312
400
401.408
398.1312
400
399.36
400
399.36
398.1312
400
398.6773333
Error
0.0023%
0.0047%
-
0.0035%
0.0047%
-
0.0016%
-
0.0016%
0.0047%
0.0047%
0.0033%
Table 23-10. Clock Characteristics
Parameter
f_IOSC
f_IOSC30KHZ
f_XOSC
f_{XOSC_XTAL}
Parameter Name
Internal 12 MHz oscillator frequency
Internal 30 KHz oscillator frequency
Hibernation module oscillator frequency
Crystal reference for hibernation oscillator
Min
Nom
8.4
12
15
30
-
4.194304
-
4.194304
Max
15.6
45
-
-
Unit
MHz
KHz
MHz
MHz
580
April 05, 2010
Texas Instruments-Production Data