ST72521R9-Auto STMicroelectronics, ST72521R9-Auto Datasheet - Page 85

• Manufacturer Part Number: ST72521R9-Auto
• Description: 8-bit MCU for automotive
• Manufacturer: STMicroelectronics

Specifications of ST72521R9-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

ST72521xx-Auto
11
11.1
11.2
11.3
Caution:
11.4
11.5
Main clock controller with real-time clock and beeper
(MCC/RTC)
Introduction
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
for more 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 a f
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
more details.
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
Main clock controller with real-time clock and beeper (MCC/RTC)
CPU
Doc ID 17660 Rev 1
main clock frequency and is controlled by three bits in the
Section 8.4: Active Halt and Halt modes on page 68
Section 8.2: Slow mode on page 65
OSC2
are available.
CPU
clock to
85/276
for