st72324bk STMicroelectronics, st72324bk Datasheet - Page 61

• Manufacturer Part Number: st72324bk
• Description: 3 V/5 V Range 8-bit Mcu With 4/8 Kbyte Rom, 10-bit Adc, Four Timers And Spi
• Manufacturer: STMicroelectronics

ST72323 ST72323L
9.2
9.2.1
9.2.2
Caution:
9.2.3
9.2.4
Main clock controller with real-time clock and beeper
(MCC/RTC)
The main clock controller consists of three different functions:
●
●
●
Each function can be used independently and simultaneously.
Programmable CPU clock prescaler
The programmable CPU clock prescaler supplies the clock for the ST7 CPU and its internal
peripherals. It manages Slow power saving mode (See
details).
The prescaler selects the f
MCCSR register: CP[1:0] and SMS.
Clock-out capability
The clock-out capability is an alternate function of an I/O port pin that outputs the f
to drive external devices. It is controlled by the MCO bit in the MCCSR register.
When selected, the clock out pin suspends the clock during Active-Halt mode.
Real-time clock timer (RTC)
The counter of the real-time clock timer allows an interrupt to be generated based on an
accurate real-time clock. Four different time bases depending directly on f
The whole functionality is controlled by four bits of the MCCSR register: TB[1:0], OIE and
OIF.
When the RTC interrupt is enabled (OIE bit set), the ST7 enters Active-Halt mode when the
Halt instruction is executed. See
Beeper
The beep function is controlled by the MCCBCR register. It can output three selectable
frequencies on the BEEP pin (I/O port alternate function).
a programmable CPU clock prescaler
a clock-out signal to supply external devices
a real-time clock timer with interrupt capability
CPU
main clock frequency and is controlled by three bits in the
Section 7.4: Active-Halt and Halt modes
Section 7.2: Slow mode
On-chip peripherals
OSC2
for more details.
are available.
for more
CPU
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clock