ST7FLI19BY1M3TR STMicroelectronics, ST7FLI19BY1M3TR Datasheet - Page 55

• Manufacturer Part Number: ST7FLI19BY1M3TR
• Description: IC MCU 8BIT 4K FLASH 16SOIC
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST7FLI19BY1M3TR

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 17
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 7x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

11 ON-CHIP PERIPHERALS
11.1 WATCHDOG TIMER (WDG)
11.1.1 Introduction
The Watchdog timer is used to detect the occur-
rence of a software fault, usually generated by ex-
ternal interference or by unforeseen logical condi-
tions, which causes the application program to
abandon its normal sequence. The Watchdog cir-
cuit generates an MCU reset on expiry of a pro-
grammed time period, unless the program refresh-
es the counter’s contents before the T6 bit be-
comes cleared.
11.1.2 Main Features
■
■
■
Figure 34. Watchdog Block Diagram
Programmable free-running downcounter (64
increments of 16000 CPU cycles)
Programmable reset
Reset (if watchdog activated) when the T6 bit
reaches zero
f
CPU
WDGA
RESET
T6
T5
WATCHDOG CONTROL REGISTER (CR)
7-BIT DOWNCOUNTER
CLOCK DIVIDER
T4
÷16000
T3
■
■
11.1.3 Functional Description
The counter value stored in the CR register (bits
T[6:0]), is decremented every 16000 machine cy-
cles, and the length of the timeout period can be
programmed by the user in 64 increments.
If the watchdog is activated (the WDGA bit is set)
and when the 7-bit timer (bits T[6:0]) rolls over
from 40h to 3Fh (T6 becomes cleared), it initiates
a reset cycle pulling low the reset pin for typically
30µs.
T2
Optional
(configurable by option byte)
Hardware Watchdog selectable by option byte
T1
reset
T0
on
HALT
ST7LITE1xB
instruction
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