C8051F901-GU Silicon Laboratories Inc, C8051F901-GU Datasheet - Page 188

• Manufacturer Part Number: C8051F901-GU
• Description: IC MCU 8BIT 8KB FLASH 24QSOP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F9xxr

Specifications of C8051F901-GU

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 24-QSOP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 3.6 V
• Data Converters: A/D 15x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F9x
• Core: 8051
• Data Ram Size: 768 B
• Interface Type: UART
• Maximum Clock Frequency: 25 MHz
• Number Of Timers: 4
• Operating Supply Voltage: 0.9 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F912DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 24QSOP
• Device Core: 8051
• Family Name: C8051F90x
• Maximum Speed: 25 MHz
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1847-5

C8051F91x-C8051F90x
20. SmaRTClock (Real Time Clock)
C8051F91x-C8051F90x devices include an ultra low power 32-bit SmaRTClock Peripheral (Real Time
Clock) with alarm. The SmaRTClock has a dedicated 32 kHz oscillator that can be configured for use with
or without a crystal. No external resistor or loading capacitors are required. The on-chip loading capacitors
are programmable to 16 discrete levels allowing compatibility with a wide range of crystals. The
SmaRTClock can operate directly from a 0.9–3.6 V battery voltage and remains operational even when the
device goes into its lowest power down mode. On ‘F912 and ‘F902 devices, the SmaRTClock output can
be buffered and routed to a GPIO pin to provide an accurate, low frequency clock to other devices while
the MCU is in its lowest power down mode (see “PMU0MD: Power Management Unit Mode” on page 150
for more details). ‘F912 and ‘F902 devices also support an ultra low power internal LFO that reduces sleep
mode current.
The SmaRTClock allows a maximum of 36 hour 32-bit independent time-keeping when used with a
32.768 kHz Watch Crystal. The SmaRTClock provides an Alarm and Missing SmaRTClock events, which
could be used as reset or wakeup sources. See Section “18. Reset Sources” on page 171 and Section
“14. Power Management” on page 143 for details on reset sources and low power mode wake-up sources,
respectively.
188
XTAL4
Registers
Programmable Load Capacitors
Internal
SmaRTClock State Machine
SmaRTClock Oscillator
SmaRTClock
Figure 20.1. SmaRTClock Block Diagram
CAPTUREn
RTC0XCN
RTC0XCF
RTC0PIN
ALARMn
RTC0CN
XTAL3
Wake-Up
Interrupt
Rev. 1.0
RTCOUT
RTC0KEY
RTC0ADR
RTC0DAT
Registers
Interface
available on ‘F912 and ‘F902 devices.
Buffered clock output and LFO only
SmaRTClock
32-Bit
Timer
LFO
Power/
Clock
Mgmt