ST7263BK1 STMicroelectronics, ST7263BK1 Datasheet - Page 40

• Manufacturer Part Number: ST7263BK1
• Description: LOW SPEED USB 8-BIT MCU FAMILY WITH UP TO 32K FLASH/ROM, DFU CAPABILITY, 8-BIT ADC, WDG, TIMER, SCI and I2C
• Manufacturer: STMicroelectronics

Specifications of ST7263BK1

• 4, 8, 16 Or 32 Kbytes Program Memory: high density Flash (HDFlash), FastROM or ROM with Read-Out and Write protection

Power saving modes
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Power saving modes
Introduction
To give a large measure of flexibility to the application in terms of power consumption, two
main power saving modes are implemented in the ST7.
After a Reset, the normal operating mode is selected by default (Run mode). This mode
drives the device (CPU and embedded peripherals) by means of a master clock which is
based on the main oscillator frequency divided by 3 (f
From Run mode, the different power saving modes may be selected by setting the relevant
register bits or by calling the specific ST7 software instruction whose action depends on the
oscillator status.
Halt mode
The MCU consumes the least amount of power in Halt mode. The Halt mode is entered by
executing the Halt instruction. The internal oscillator is then turned off, causing all internal
processing to be stopped, including the operation of the on-chip peripherals.
When entering Halt mode, the I bit in the Condition Code register is cleared. Thus, all
external interrupts (ITi or USB end suspend mode) are allowed and if an interrupt occurs,
the CPU clock becomes active.
The MCU can exit Halt mode on reception of either an external interrupt on ITi, an end
suspend mode interrupt coming from USB peripheral, or a reset. The oscillator is then
turned on and a stabilization time is provided before releasing CPU operation. The
stabilization time is 4096 CPU clock cycles.
After the start up delay, the CPU continues operation by servicing the interrupt which wakes
it up or by fetching the reset vector if a reset wakes it up.
Doc ID 7516 Rev 8
CPU
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ST7263Bxx