C8051F326DK Silicon Laboratories Inc, C8051F326DK Datasheet - Page 71

• Manufacturer Part Number: C8051F326DK
• Description: KIT DEV FOR C8051F326/7
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F326DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F326/F327
• Interface Type: USB
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F326
• Silicon Family Name: C8051F32x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Silicon Laboratories C8051F326, C8051F327
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1306

10. Oscillators
C8051F326/7 devices include a programmable internal oscillator, an external clock input circuit, a low fre-
quency internal oscillator, and a 4x Clock Multiplier. The internal oscillator can be enabled/disabled and
calibrated using the OSCICN and OSCICL registers, as shown in Figure 10.1. The Low Frequency oscilla-
tor can be enabled/disabled and calibrated using the OSCLCN register, as shown in Figure 10.3. The sys-
tem clock (SYSCLK) can be derived from the internal oscillator, external clock, low frequency oscillator, or
the 4x Clock Multiplier divided by 2. The USB clock (USBCLK) can be derived from the internal oscillator
divided by 2, external clock, or 4x Clock Multiplier. Oscillator electrical specifications are given in
Table 10.3 on page 78.
10.1. Programmable Internal Oscillator
All C8051F326/7 devices include a programmable internal oscillator that defaults as the system clock after
a system reset. The internal oscillator period can be adjusted via the OSCICL register. On C8051F326/7
devices, OSCICL is factory calibrated to obtain a 12 MHz frequency. Electrical specifications for the preci-
sion internal oscillator are given in Table 10.3 on page 78. Note that the system clock may be derived from
the programmed internal oscillator divided by 1, 2, 4, or 8, as defined by the IFCN bits in register OSCICN.
The divide value defaults to 8 following a reset.
CMOS
Clock
XTAL2
OSCICL
Low Frequency
OSCLF
Figure 10.1. Oscillator Diagram
Programmable
Internal Clock
Generator
Oscillator
Circuit
Input
EN
EN
IOSC
EXOSC
OSCICN
EXOSC
Rev. 1.1
IOSC
CLKMUL
n
Clock Multiplier
OSCLCN
x 2
x 2
OFF (0 Hz)
IOSC / 2
EXOSC
C8051F326/7
CLKSEL
SYSCLK
USBCLK
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