STM32W108CBU63TR STMicroelectronics, STM32W108CBU63TR Datasheet - Page 39

• Manufacturer Part Number: STM32W108CBU63TR
• Description: 16/32-BITS MICROS
• Manufacturer: STMicroelectronics
• Series: STM32r

Specifications of STM32W108CBU63TR

• Applications: RF4CE, Remote Control
• Core Processor: ARM® Cortex-M3™
• Program Memory Type: FLASH (128 kB)
• Controller Series: STM32W
• Ram Size: 8K x 8
• Interface: I²C, SPI, UART/USART
• Number Of I /o: 24
• Voltage - Supply: 1.18 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-VFQFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

STM32W108CB, STM32W108HB
6.3.1
Figure 6
shows all the clock sources and the general areas of the chip to which they are routed.
Figure 6.
High-frequency internal RC oscillator (OSCHF)
The high-frequency RC oscillator (OSCHF) is used as the default system clock source when
power is applied to the core domain. The nominal frequency coming out of reset is 12 MHz.
Most peripherals, excluding the radio peripheral, are fully functional using the OSCHF clock
source. Application software must be aware that peripherals are clocked at different speeds
depending on whether OSCHF or OSC24M is being used. Since the frequency step of
OSCHF is 0.5 MHz and the high-frequency crystal oscillator is used for calibration, the
digital in
32kHz
12MHz
24MHz
XTAL
RC
Sleep Timer
Watchdog
counter
TIMx_SMCR[2:0]
counter
counter
TIMx
shows a block diagram of the clocks in the STM32W108. This simplified view
10kHz
32kHz
XTAL
RC
Clocks block diagram
OSCRC
OSC24M_CTRL[1]
TIMx_OR[1:0]
oscillator
OSC24M_CTRL[0]
(selects RC when
Failover monitor
SLEEPTMR _CFG[7:4]
SLEEPTMR _CLKEN[0]
XTAL fails )
(nominal 10)
/(2^N)
oscillator
/N
OSC 24M
Doc ID 16252 Rev 8
OSCHF
SLEEPTMR _CFG[0]
OSC32K
CLK1K
TIMxCLK
digital in
SCLK
/2
PCLK
CPU_CLKSEL[0]
DEBUG_EMCR[24]
FCLK
MAC Timer
AND
RATEGEN
counter
SCx
/2
System modules
Produces 6MHz
ADC_CFG[2]
or 1MHz
RAM CTRL
ST _CSR[2]
FLITF
SysTick
counter
CPU
SigmaDelta
bus
bus
TRACECLK
ADC
SCxSCLK
digital out
digital i /o
Flash
RAM
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