LM3S2110 Datasheet, PDF (453/485 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S2110 Microcontroller
20.2
20.2.1
AC Characteristics
Load Conditions
Unless otherwise specified, the following conditions are true for all timing measurements. Timing
measurements are for 4-mA drive strength.
Figure 20-1. Load Conditions
pin
C_L = 50 pF
GND
20.2.2
Clocks
Table 20-6. Phase Locked Loop (PLL) Characteristics
Parameter Parameter Name
Min Nom Max Unit
f_{ref_crystal} Crystal reference^a
3.579545 - 8.192 MHz
f_{ref_ext}
f_pll
External clock reference^a 3.579545 - 8.192 MHz
PLL frequency^b
-
400 - 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 20-7. Clock Characteristics
Parameter Parameter Name
Min Nom Max Unit
f_IOSC
f_IOSC30KHZ
f_MOSC
Internal 12 MHz oscillator frequency
Internal 30 KHz oscillator frequency
Main oscillator frequency
8.4 12 15.6 MHz
21 30 39 KHz
1 - 8 MHz
t_{MOSC_per}
Main oscillator period
125 - 1000 ns
f_{ref_crystal_bypass} Crystal reference using the main oscillator (PLL in BYPASS mode) 1 -
8 MHz
f_{ref_ext_bypass} External clock reference (PLL in BYPASS mode)
0 - 25 MHz
f_{system_clock}
System clock
0 - 25 MHz
Table 20-8. Crystal Characteristics
Parameter Name
Frequency
Frequency tolerance
Aging
Oscillation mode
Temperature stability (0 - 85 °C)
Motional capacitance (typ)
Value
Units
8
6
4
3.5 MHz
±50 ±50 ±50 ±50 ppm
±5
±5
±5
±5 ppm/yr
Parallel Parallel Parallel Parallel
±25 ±25 ±25 ±25 ppm
27.8 37.0 55.6 63.5 pF
November 29, 2007
453
Preliminary