PIC16F87-I/ML Microchip Technology, PIC16F87-I/ML Datasheet - Page 46

• Manufacturer Part Number: PIC16F87-I/ML
• Description: IC MCU FLASH 4KX14 EEPROM 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F87-I/ML

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC16F
• No. Of I/o's: 16
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28QFN3 - SOCKET TRAN ICE 18DIP/28QFNAC164322 - MODULE SOCKET MPLAB PM3 28/44QFNAC164033 - ADAPTER 28QFN TO 18DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Data Converters: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC16F87/88
4.7.2
The core and peripherals can be configured to be
clocked by T1OSC using a 32.768 kHz crystal. The
crystal must be connected to the T1OSO and T1OSI
pins. This is the same configuration as the low-power
timer circuit (see Section 7.6 “Timer1 Oscillator”).
When SCS bits are configured to run from T1OSC, a
clock transition is generated. It will clear the OSTS bit,
switch the system clock from either the primary system
clock or INTRC, depending on the value of SCS<1:0>
and FOSC<2:0>, to the external low-power Timer1
oscillator input (T1OSC) and shut down the primary
system clock to conserve power.
After a clock switch has been executed, the internal Q
clocks are held in the Q1 state until eight falling edge
clocks are counted on the T1OSC. After the eight
clock periods have transpired, the clock input to the Q
clocks is released and operation resumes (see
Figure 4-8). In addition, T1RUN (In T1CON) is set to
indicate that T1OSC is being used as the system
clock.
FIGURE 4-8:
DS30487C-page 44
Note 1: T
SCS<1:0>
Program
Counter
System
T1OSI
OSC1
Clock
2: T
3: T
4: T
Q1
SEC_RUN MODE
OSC
SCS
T
DLY
1
T
OSC
P
Q2
= 8 T
= 1 T
= 30.52 s.
= 50 ns minimum.
PC
(2)
Q3
T
T
Q4
1
1
P
P
TIMING DIAGRAM FOR SWITCHING TO SEC_RUN MODE
.
T
Q1
DLY (4)
T
T
1
P
(1)
T
SCS
(3)
PC +1
Note 1: The T1OSCEN bit must be enabled and it
Q1
2: When T1OSCEN = 0, the following possible
Q2
A clock switching event will occur if the
final state of the SCS bits is different from
the original.
is the user’s responsibility to ensure
T1OSC is stable before clock switching to
the T1OSC input clock can occur.
effects result.
SCS<1:0>
Original
Q3
00
00
10
10
Q4
 2005 Microchip Technology Inc.
SCS<1:0>
Modified
Q1
01
11
11
01
Q2
PC + 2
00 – no change
10 – INTRC
10 – no change
00 – Oscillator
defined by
FOSC<2:0>
Q3
SCS<1:0>
Final
Q4
PC + 3
Q1