PIC16F74T-I/ML Microchip Technology, PIC16F74T-I/ML Datasheet - Page 103

• Manufacturer Part Number: PIC16F74T-I/ML
• Description: IC MCU FLASH 4KX14 A/D 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F74T-I/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: FLASH
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000, DM163022
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

12.13 Watchdog Timer (WDT)
The Watchdog Timer is a free running on-chip RC oscil-
lator, which does not require any external components.
This RC oscillator is separate from the RC oscillator of
the OSC1/CLKIN pin. That means that the WDT will
run, even if the clock on the OSC1/CLKIN and OSC2/
CLKOUT pins of the device has been stopped, for
example, by execution of a SLEEP instruction.
During normal operation, a WDT time-out generates a
device RESET (Watchdog Timer Reset). If the device is
in SLEEP mode, a WDT time-out causes the device to
wake-up and continue with normal operation (Watch-
dog Timer Wake-up). The TO bit in the STATUS regis-
ter will be cleared upon a Watchdog Timer time-out.
The WDT can be permanently disabled by clearing
configuration bit, WDTE (Section 12.1).
FIGURE 12-11:
TABLE 12-7:
 2002 Microchip Technology Inc.
2007h
81h,181h
Legend: Shaded cells are not used by the Watchdog Timer.
Address
Note 1: See Register 12-1 for operation of these bits.
Note: PSA and PS2:PS0 are bits in the OPTION_REG register.
Config. bits
OPTION_REG
SUMMARY OF WATCHDOG TIMER REGISTERS
Name
WATCHDOG TIMER BLOCK DIAGRAM
WDT Timer
Enable Bit
WDT
RBPU
From TMR0 Clock Source
(Figure 5-1)
Bit 7
(1)
BODEN
INTEDG
Bit 6
0
1
(1)
PSA
M
U
X
T0CS
Bit 5
—
WDT time-out period values may be found in the Elec-
trical Specifications section under parameter #31. Val-
ues for the WDT prescaler (actually a postscaler, but
shared with the Timer0 prescaler) may be assigned
using the OPTION_REG register.
T0SE
Bit 4
CP0
0
Note 1: The CLRWDT and SLEEP instructions
Time-out
8 - to - 1 MUX
MUX
WDT
Postscaler
2: When a CLRWDT instruction is executed
PWRTE
1
clear the WDT and the postscaler, if
assigned to the WDT, and prevent it from
timing out and generating a device
RESET condition.
Bit 3
PSA
and the prescaler is assigned to the WDT,
the prescaler count will be cleared, but
the prescaler assignment is not changed.
8
(1)
PSA
To TMR0 (Figure 5-1)
WDTE
Bit 2
PS2
PS2:PS0
PIC16F7X
FOSC1
Bit 1
PS1
DS30325B-page 101
FOSC0
Bit 0
PS0