C8051F360/1/2/3/4/5/6/7/8/9
SFR Definition 16.2. OSCICN: Internal Oscillator Control
SFR Page:
F
SFR Address: 0xB7
R/W
R
R/W
R
R/W
R/W
R/W
R/W
Reset Value
IOSCEN
IFRDY SUSPEND Reserved Reserved Reserved IFCN1
IFCN0 11000000
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Bit 7:
IOSCEN: Internal Oscillator Enable Bit.
0: Internal Oscillator Disabled.
1: Internal Oscillator Enabled.
Bit 6:
IFRDY: Internal Oscillator Frequency Ready Flag.
0: Internal Oscillator not running at programmed frequency.
1: Internal Oscillator running at programmed frequency.
SUSPEND: Internal Oscillator Suspend Enable Bit.
Bits 5:
Setting this bit to logic ‘1’ places the internal oscillator in SUSPEND mode. The internal
oscillator resumes operation when one of the SUSPEND mode awakening events occur.
Bits 4–2: RESERVED. Read = 000b. Must Write 000b.
Bits 1–0: IFCN1-0: Internal Oscillator Frequency Control Bits.
00: Internal Oscillator is divided by 8. (default)
01: Internal Oscillator is divided by 4.
10: Internal Oscillator is divided by 2.
11: Internal Oscillator is divided by 1.
Table 16.1. Internal High Frequency Oscillator Electrical Characteristics
–40°C to +85°C unless otherwise specified.
Parameter
Calibrated Internal Oscillator
Frequency
Conditions
Min
Typ
Max
Units
24
24.5
25
MHz
Internal Oscillator Supply
OSCICN.7 = 1
—
450
600
µA
Current (from V
)
DD
Power Supply Sensitivity
Temperature Sensitivity
External Clock Frequency
Constant Temperature
Constant Supply
—
—
0
0.12
60
—
—
—
30
—
%/V
ppm/°C
MHz
T
(External Clock High Time)
15
—
ns
XCH
XCL
T
(External Clock Low Time)
15
—
—
ns
16.2. Programmable Internal Low-Frequency (L-F) Oscillator
All C8051F36x devices include a programmable low-frequency internal oscillator, which is calibrated to a
nominal frequency of 80 kHz. The low-frequency oscillator circuit includes a divider that can be changed to
divide the clock by 1, 2, 4, or 8, using the OSCLD bits in the OSCLCN register (see SFR Definition 16.3).
Additionally, the OSCLF bits (OSCLCN5:2) can be used to adjust the oscillator’s output frequency.
Rev. 1.0
171
SILICON [ SILICON ]
