ST7FLITE39F2U6 STMicroelectronics, ST7FLITE39F2U6 Datasheet - Page 53

• Manufacturer Part Number: ST7FLITE39F2U6
• Description: IC MCU 8BIT 8K FLASH 20QFN
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST7FLITE39F2U6

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: LINSCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 15
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 7x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-QFN
• For Use With: 497-8406 - BOARD STF20NM50FD/STF7LITE39BF2497-8403 - BOARD DEMO STCC08 AC SW DETECTOR497-6398 - BOARD EVAL ST7FLITE39/STM1403497-5858 - EVAL BOARD PLAYBACK ST7FLITE497-5514 - EVAL BOARD THERMO CONTROL REFRIG497-5049 - KIT STARTER RAISONANCE ST7FLITE
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5635

WATCHDOG TIMER (Cont’d)
The application program must write in the CR reg-
ister at regular intervals during normal operation to
prevent an MCU reset. This downcounter is free-
running: it counts down even if the watchdog is
disabled. The value to be stored in the CR register
must be between FFh and C0h (see
.Watchdog
– The WDGA bit is set (watchdog enabled)
– The T6 bit is set to prevent generating an imme-
– The T[5:0] bits contain the number of increments
Following a reset, the watchdog is disabled. Once
activated it cannot be disabled, except by a reset.
The T6 bit can be used to generate a software re-
set (the WDGA bit is set and the T6 bit is cleared).
If the watchdog is activated, the HALT instruction
will generate a Reset.
diate reset
which represents the time delay before the
watchdog produces a reset.
Timing):
Table 14
Table 14.Watchdog Timing
Notes: The timing variation shown in
due to the unknown status of the prescaler when
writing to the CR register.
11.1.4 Hardware Watchdog Option
If Hardware Watchdog is selected by option byte,
the watchdog is always active and the WDGA bit in
the CR is not used.
Refer to the Option Byte description in
15.1 on page
11.1.4.1 Using Halt Mode with the WDG
(WDGHALT option)
If Halt mode with Watchdog is enabled by option
byte (No watchdog reset on HALT instruction), it is
recommended before executing the HALT instruc-
tion to refresh the WDG counter, to avoid an unex-
pected WDG reset immediately after waking up
the microcontroller.
Counter
Code
WDG
C0h
FFh
161.
f
CPU
[ms]
= 8MHz
min
127
1
ST7LITE3xF2
Table 14
[ms]
max
128
2
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