str755fvx STMicroelectronics, str755fvx Datasheet - Page 7

• Manufacturer Part Number: str755fvx
• Description: Arm7tdmi-s, 32-bit Mcu With Flash, Smi, 3 Std 16-bit Timers Pwm Timer, Fast 10-bit Adc, I2c, Uart, Ssp, Usb And Can
• Manufacturer: STMicroelectronics

STR750F
Caution:
Low Power modes
The STR750F supports 5 low power modes, SLOW, PCG, WFI, STOP and STANDBY.
G
G
G
G
G
It is important to bear in mind that it is forbidden to remove power from the V
supply in any of the Low Power Modes (even in STANDBY MODE).
DMA
The flexible 4-channel general-purpose DMA is able to manage memory to memory,
peripheral to memory and memory to peripheral transfers. The DMA controller supports
circular buffer management avoiding the generation of interrupts when the controller
reaches the end of the buffer.
The DMA can be used with the main peripherals: UART0, SSP0, Motor control PWM timer
(PWM), standard timer TIM0 and ADC.
RTC (Real Time Clock)
The real time clock provides a set of continuously running counters which can be used with
suitable software to provide a clock calendar function, and provides an alarm interrupt and a
periodic interrupt. It is clocked by an external 32.768 kHz oscillator or the internal low power
RC oscillator. The RC has a typical frequency of 300 kHz and can be calibrated.
WDG (Watchdog Timer)
The watchdog timer is based on a 16-bit downcounter and 8-bit prescaler. It can be used as
watchdog to reset the device when a problem occurs, or as free running timer for application
time out management.
SLOW MODE: the system clock speed is reduced. Alternatively, the PLL and the main
oscillator can be stopped and the device is driven by a low power clock (f
clock is either an external 32.768 kHz oscillator or the internal low power RC oscillator.
PCG MODE (Peripheral Clock Gating MODE): When the peripherals are not used, their
APB clocks are gated to optimize the power consumption.
WFI MODE (Wait For Interrupts): only the CPU clock is stopped, all peripherals
continue to work and can wake-up the CPU when IRQs occur.
STOP MODE: all clocks/peripherals are disabled. It is also possible to disable the
oscillators and the Main Voltage Regulator (In this case the V
by V
SRAM and registers contents retained. The system can be woken up by any of the
external interrupts / wake-up lines or by the RTC timer which can optionally be kept
running. The RTC can be clocked either by the 32.768 kHz Crystal or the Low Power
RC Oscillator.
Alternatively, STOP mode gives flexibility to keep the either main oscillator, or the Flash
or the Main Voltage Regulator enabled when a fast start after wake-up is preferred (at
the cost of some extra power consumption).
STANDBY MODE: This mode (only available in single supply power schemes) is
intended to achieve the lowest power consumption even when the temperature is
increasing. The digital power supply (V
at high ambient temperature). SRAM and all register contents are lost. Only the RTC
remains powered by V
RUN mode by a trigger event on the WKP_STDBY pin or an alarm timeout on the RTC
counter.
18_BKP
). This mode is intended to achieve the lowest power consumption with
18_BKP
. The STR750F can be switched back from STANDBY to
CORE
) is completely removed (no leakage even
CORE
is entirely powered
DD_IO
RTC
Introduction
). The
power
7/71