L9803 datasheet(24/126 Pages) STMICROELECTRONICS

No de pièce	L9803

Description	Super smart power motor driver with 8-Bit MCU, RAM, EEPROM, ADC, WDG, Timers, PWM and H-bridge driver

PDF	126 Pages

Scroll/Zoom	100%

Fabricant	STMICROELECTRONICS [STMicroelectronics]

Site Internet	http://www.st.com

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24 / 126 page

Clocks, Reset, Interrupts & Power saving modes

L9803

24/126

Reset Value:0000 0000 (00h)

b0 - Slow Mode Select

0- Normal mode - Oscillator frequency / 2 (Reset state)

1- Slow mode (Bits b1 and b2 define the prescaler factor)

b1, b2 - CPU clock prescaler for Slow Mode

b3, b4 - External Interrupt Option

The selection issued from b3/b4 combination is applied to PA[0]..PA[7],PB0,PB1 external

interrupt. The selection can be made only if I bit in CC register is reset (interrupt enabled).

b3, b4 can be written only when the Interrupt Mask (I) of the CC (Condition Code) register is

set to 1.

b5,b6,b7 = not used

3.5

Reset

3.5.1

Introduction

There are four sources of Reset:

–

NRESET pin (external source)

–

Power-On Reset / Low Voltage Detection (Internal source)

–

WATCHDOG (Internal Source)

–

SAFEGUARD (Internal source)

The Reset Service Routine vector is located at address FFFEh-FFFFh.

b4b3

b1b0

Option

Oscillator frequency / 4

Oscillator frequency / 8

Oscillator frequency / 16

Oscillator frequency / 32

Option

Falling edge and low level (Reset state)

Falling edge only

Rising edge only

Rising and Falling edge

L9803 Fiches technique(PDF) 24 Page - STMicroelectronics