PIC16F946T-I/PT Microchip Technology, PIC16F946T-I/PT Datasheet - Page 195

• Manufacturer Part Number: PIC16F946T-I/PT
• Description: Microcontroller
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F946T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 336 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MA160011 - DAUGHTER BOARD PICDEM LCD 16F91X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

16.2
The PIC16F946 differentiates between various kinds of
Reset:
a)
b)
c)
d)
e)
f)
Some registers are not affected in any Reset condition;
their status is unknown on POR and unchanged in any
other Reset. Most other registers are reset to a “Reset
state” on:
• Power-on Reset
• MCLR Reset
• MCLR Reset during Sleep
• WDT Reset
• Brown-out Reset (BOR)
FIGURE 16-1:
© 2005 Microchip Technology Inc.
MCLR/V
Power-on Reset (POR)
WDT Reset during normal operation
WDT Reset during Sleep
MCLR Reset during normal operation
MCLR Reset during Sleep
Brown-out Reset (BOR)
CLKI pin
OSC1/
V
Note 1:
DD
Reset
PP
pin
LFINTOSC
OST/PWRT
Refer to the Configuration Word register (Register 16-1).
Brown-out
V
Module
DD
Detect
WDT
Reset
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
Rise
OST
PWRT
(1)
10-bit Ripple Counter
WDT
Time-out
Reset
11-bit Ripple Counter
SBOREN
BOREN
Power-on Reset
External
Reset
SLEEP
Preliminary
They are not affected by a WDT wake-up since this is
viewed as the resumption of normal operation. TO and
PD bits are set or cleared differently in different Reset
situations, as indicated in Table 16-2. These bits are
used in software to determine the nature of the Reset.
See Table 16-5 for a full description of Reset states of
all registers.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 16-1.
The MCLR Reset path has a noise filter to detect and
ignore small pulses. See Section 19.0 “Electrical
Specifications” for pulse width specifications.
Enable PWRT
Enable OST
PIC16F946
S
R
DS41265A-page 193
Q
Chip_Reset