PIC16F1937-I/P Microchip Technology, PIC16F1937-I/P Datasheet - Page 73

• Manufacturer Part Number: PIC16F1937-I/P
• Description: IC PIC MCU FLASH 512KX14 40-PDIP
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16F1937-I/P

• Program Memory Type: FLASH
• Program Memory Size: 14KB (8K x 14)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 32MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 36
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: EUSART/MI2C/SPI
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14-ch x 10-bit
• A/d Bit Size: 10 bit
• A/d Channels Available: 14
• Height: 4.95 mm
• Length: 53.21 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Width: 14.73 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

4.1
Interrupts are disabled upon any device Reset. They
are enabled by setting the following bits:
• GIE bit of the INTCON register
• Interrupt Enable bit(s) for the specific interrupt
• PEIE bit of the INTCON register (if the Interrupt
The INTCON, PIR1, PIR2 and PIR3 registers record
individual interrupts via interrupt flag bits. Interrupt flag
bits will be set, regardless of the status of the GIE, PEIE
and individual interrupt enable bits.
The following events happen when an interrupt event
occurs while the GIE bit is set:
• Current prefetched instruction is flushed
• GIE bit is cleared
• Current Program Counter (PC) is pushed onto the
• PC is loaded with the interrupt vector 0004h
The ISR determines the source of the interrupt by
polling the interrupt flag bits. The interrupt flag bits must
be cleared before exiting the ISR to avoid repeated
interrupts. Because the GIE bit is cleared, any interrupt
FIGURE 4-3:
© 2008 Microchip Technology Inc.
INSTRUCTION FLOW
event(s)
Enable bit of the interrupt event is contained in the
PIE1, PIE2 and PIE3 registers)
stack
GIE bit
(INTCON<7>)
INTF flag
(INTCON<1>)
CLKOUT
INT pin
OSC1
Instruction
Executed
Note 1: INTF flag is sampled here (every Q1).
Instruction
Fetched
PC
Operation
2: Asynchronous interrupt latency = 3-5 T
3: CLKOUT is available only in INTOSC and RC Oscillator modes.
4: For minimum width of INT pulse, refer to AC specifications in Section 28.0 “Electrical Specifications”.
5: INTF is enabled to be set any time during the Q4-Q1 cycles.
(3)
Latency is the same whether Inst (PC) is a single cycle or a 2-cycle instruction.
Q1
Inst (PC – 1)
Inst (PC)
(1)
INT PIN INTERRUPT TIMING
Q2
PC
Q3
(4)
Q4
(5)
Q1
Inst (PC + 1)
Inst (PC)
Q2
(1)
PC + 1
Q3
CY
Preliminary
. Synchronous latency = 3-4 T
Q4
Interrupt Latency
Q1
Dummy Cycle
Q2
that occurs while executing the ISR will be recorded
through its interrupt flag, but will not cause the
processor to redirect to the interrupt vector.
The RETFIE instruction exits the ISR by popping the
previous address from the stack, restoring the saved
context from the shadow registers and setting the GIE
bit.
For additional information on a specific interrupt’s
operation, refer to its peripheral chapter.
4.2
Interrupt latency is defined as the time from when the
interrupt event occurs to the time code execution at the
interrupt vector begins. The latency for synchronous
interrupts is 3 or 4 instruction cycles. For asynchronous
interrupts, the latency is 3 to 5 instruction cycles,
depending on when the interrupt occurs. See Figure 4-3
for timing details.
PC + 1
—
PIC16F193X/LF193X
Note 1: Individual interrupt flag bits are set,
Q3
2: All interrupts will be ignored while the GIE
Q4
Interrupt Latency
(2)
regardless of the state of any other
enable bits.
bit is cleared. Any interrupt occurring
while the GIE bit is clear will be serviced
when the GIE bit is set again.
Q1
Dummy Cycle
CY
Inst (0004h)
, where T
Q2
0004h
Q3
CY
Q4
= instruction cycle time.
Q1
DS41364A-page 71
Inst (0005h)
Q2
Inst (0004h)
0005h
Q3
Q4