Datasheet

DocID14611 Rev 10 19/136
STM32F103xC, STM32F103xD, STM32F103xE Description
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periodic interrupt. It is clocked by a 32.768 kHz external crystal, resonator or oscillator, the
internal low power RC oscillator or the high-speed external clock divided by 128. The
internal low-speed RC has a typical frequency of 40 kHz. The RTC can be calibrated using
an external 512 Hz output to compensate for any natural quartz deviation. The RTC features
a 32-bit programmable counter for long term measurement using the Compare register to
generate an alarm. A 20-bit prescaler is used for the time base clock and is by default
configured to generate a time base of 1 second from a clock at 32.768 kHz.
2.3.17 Timers and watchdogs
The high-density STM32F103xx performance line devices include up to two advanced-
control timers, up to four general-purpose timers, two basic timers, two watchdog timers and
a SysTick timer.
Table 4 compares the features of the advanced-control, general-purpose and basic timers.
Table 4.High-density timer feature comparison
Timer
Counter
resolution
Counter
type
Prescaler
factor
DMA request
generation
Capture/compare
channels
Complementary
outputs
TIM1,
TIM8
16-bit
Up,
down,
up/down
Any integer
between 1
and 65536
Ye s 4 Ye s
TIM2,
TIM3,
TIM4,
TIM5
16-bit
Up,
down,
up/down
Any integer
between 1
and 65536
Ye s 4 N o
TIM6,
TIM7
16-bit Up
Any integer
between 1
and 65536
Ye s 0 N o