LM3S1150-IQC50 Luminary Micro, Inc., LM3S1150-IQC50 Datasheet - Page 73

• Manufacturer Part Number: LM3S1150-IQC50
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

June 14, 2007
Bit/Field
19:17
16:14
9:6
5:4
13
12
11
10
OSCSRC
PWMDIV
reserved
reserved
BYPASS
reserved
PWRDN
Name
XTAL
Luminary Micro Confidential-Advance Product Information
Type
R/W
R/W
R/W
R/W
R/W
RO
RO
RO
Reset
0xB
0x7
0x1
0
1
1
1
0
Description
PWM Unit Clock Divisor
This field specifies the binary divisor used to predivide the system clock
down for use as the timing reference for the PWM module. This clock
is only power 2 divide and rising edge is synchronous without phase
shift from the system clock.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
PLL Power Down
This bit connects to the PLL PWRDN input. The reset value of 1 powers
down the PLL.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
PLL Bypass
Chooses whether the system clock is derived from the PLL output or
the OSC source. If set, the clock that drives the system is the OSC
source. Otherwise, the clock that drives the system is the PLL output
clock divided by the system divider.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
This field specifies the crystal value attached to the main oscillator. The
encoding for this field is provided in Table 6-3 on page 74.
Picks among the four input sources for the OSC. The values are:
Binary Value
000
001
010
011
100
101
110
111
Value
00
01
10
11
Input Source
Main oscillator (default)
Internal oscillator (default)
Internal oscillator / 4 (this is necessary if used as input to PLL)
reserved
Divisor
/2
/4
/8
/16
/32
/64
/64
/64 (default)
LM3S1150 Microcontroller
73