LM3S310 Luminary Micro, Inc, LM3S310 Datasheet - Page 78

• Manufacturer Part Number: LM3S310
• Description: Lm3s310 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

System Control
78
Bit/Field
19:17
16:14
9:6
13
12
10
11
PWMDIV
reserved
BYPASS
PWRDN
PLLVER
Name
XTAL
OEN
Type
R/W
R/W
R/W
R/W
R/W
R/W
RO
Reset
0xB
0x7
0
1
1
1
0
Preliminary
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 PCLK/HCLK.
Reserved bits return an indeterminate value, and should
never be changed.
PLL Power Down
This bit connects to the PLL PWRDN input. The reset value
of 1 powers down the PLL. See Table 6-4 on page 79 for
PLL mode control.
PLL Output Enable
This bit specifies whether the PLL output driver is enabled.
If cleared, the driver transmits the PLL clock to the output.
Otherwise, the PLL clock does not oscillate outside the PLL
module.
Note:
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.
PLL Verification
This bit controls the PLL verification timer function. If set,
the verification timer is enabled and an interrupt is
generated if the PLL becomes inoperative. Otherwise, the
verification timer is not enabled.
This field specifies the crystal value attached to the main
oscillator. The encoding for this field is provided in Table 6-4
on page 79.
Value
000
001
010
100
101
011
110
111
Both PWRDN and OEN must be cleared to run the
PLL.
Divisor
/2
/4
/8
/16
/32
/64
/64
/64 (default)
July 5, 2006