C8051F523A-IM Silicon Laboratories Inc, C8051F523A-IM Datasheet - Page 142

• Manufacturer Part Number: C8051F523A-IM
• Description: IC 8051 MCU 4K FLASH 10DFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F52xr

Specifications of C8051F523A-IM

• Program Memory Type: FLASH
• Program Memory Size: 4KB (4K x 8)
• Package / Case: 10-DFN
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 6
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.25 V
• Data Converters: A/D 6x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Processor Series: C8051F5x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI/UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 3
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F500DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 6-ch x 12-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1488 - KIT DEV C8051F53XA, C8051F52XA770-1006 - ISP 4PORT FOR SILABS C8051F MCU336-1455 - ADAPTER PROGRAM TOOLSTICK F520
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1491-5

C8051F52x/F52xA/F53x/F53xA
14.3. System Clock Selection
The internal oscillator requires little start-up time and may be selected as the system clock immediately fol-
lowing the OSCICN write that enables the internal oscillator. External crystals and ceramic resonators typ-
ically require a start-up time before they are settled and ready for use. The Crystal Valid Flag (XTLVLD in
register OSCXCN) is set to 1 by hardware when the external oscillator is settled. To avoid reading a false
XTLVLD in crystal mode, the software should delay at least 1 ms between enabling the external
oscillator and checking XTLVLD. RC and C modes typically require no startup time.
The CLKSL bit in register CLKSEL selects which oscillator source is used as the system clock. CLKSL
must be set to 1 for the system clock to run from the external oscillator; however the external oscillator may
still clock certain peripherals (timers, PCA) when another oscillator is selected as the system clock. The
system clock may be switched on-the-fly between the internal oscillator and external oscillator, as long as
the selected clock source is enabled and has settled.
SFR Definition 14.5. CLKSEL: Clock Select
142
Bits7–6: Unused. Read = 00b; Write = don’t care.
Bits5–4: Reserved. Read = 00b; Must write 00b.
Bit3:
Bits2–1: Reserved. Read = 00b; Must write 00b.
Bit0:
Bit7
R
-
Unused. Read = 0b; Write = don’t care.
CLKSL: System Clock Select
0: Internal Oscillator (as determined by the IFCN bits in register OSCICN).
1: External Oscillator.
Bit6
R
-
Reserved Reserved
R/W
Bit5
R/W
Bit4
Rev. 1.3
Bit3
R
-
Reserved Reserved
R/W
Bit2
R/W
Bit1
SFR Address:
CLKSL
R/W
Bit0
00000000
Reset Value
0xA9