ST7LITE49M STMicroelectronics, ST7LITE49M Datasheet - Page 58

• Manufacturer Part Number: ST7LITE49M
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST7LITE49M

• 4 Kbytes Single Voltage Extended Flash (xflash) Program Memory With Read-out Protection In-circuit Programming And In-application Programming (icp And Iap) Endurance: 10k write/erase cycles guaranteed Data retention
• 128 Bytes Data Eeprom With Read-out Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: Internal trimmable 8 MHz RC oscillator, auto-wakeup internal low power - low frequency oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-halt, Auto-wakeup from Halt, Wait and Slow
• A/d Converter: 10 input channels

Power saving modes
9.2
Note:
9.3
58/188
Slow mode
This mode has two targets:
●
●
Slow mode is controlled by the SMS bit in the MCCSR register which enables or disables
Slow mode.
In this mode, the oscillator frequency is divided by 32. The CPU and peripherals are clocked
at this lower frequency.
Slow-wait mode is activated when entering Wait mode while the device is already in Slow
mode.
Figure 25. Slow mode clock transition
Wait mode
Wait mode places the MCU in a low power consumption mode by stopping the CPU.
This power saving mode is selected by calling the ‘WFI’ instruction.
All peripherals remain active. During Wait mode, the I bit of the CC register is cleared, to
enable all interrupts. All other registers and memory remain unchanged. The MCU remains
in Wait mode until an interrupt or reset occurs, whereupon the program counter branches to
the starting address of the interrupt or reset service routine.
The MCU will remain in Wait mode until a reset or an interrupt occurs, causing it to wake up.
Refer to
To reduce power consumption by decreasing the internal clock in the device,
To adapt the internal clock frequency (f
Figure 26
for a description of the Wait mode flowchart.
SMS
f
CPU
f
OSC
Doc ID 13562 Rev 3
CPU
) to the available supply voltage.
f
OSC
NORMAL RUN MODE
/32
REQUEST
f
OSC
ST7LITE49M