PIC16F648A-I/ML Microchip Technology, PIC16F648A-I/ML Datasheet - Page 53

• Manufacturer Part Number: PIC16F648A-I/ML
• Description: IC MCU FLASH 4KX14 EEPROM 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F648A-I/ML

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: 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: 256 x 8
• Voltage - Supply (vcc/vdd): 3 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: 256Byte
• Cpu Speed: 20MHz
• No.: RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164324 - MODULE SKT FOR MPLAB 8DFN/16QFNXLT28QFN3 - SOCKET TRAN ICE 18DIP/28QFNI3DBF648 - BOARD DAUGHTER ICEPIC3AC164033 - ADAPTER 28QFN TO 18DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Data Converters: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.4
A crystal oscillator circuit is built in between pins T1OSI
(input) and T1OSO (amplifier output). It is enabled by
setting control bit T1OSCEN (T1CON<3>). It will
continue to run during Sleep. It is primarily intended for
a 32.768 kHz watch crystal. Table 7-1 shows the
capacitor selection for the Timer1 oscillator.
The user must provide a software time delay to ensure
proper oscillator start-up.
TABLE 7-1:
TABLE 7-2:
© 2005 Microchip Technology Inc.
Legend:
10Bh, 18Bh
0Bh, 8Bh,
Address
Note:
32.768 kHz
0Ch
8Ch
0Eh
0Fh
10h
Freq
Timer1 Oscillator
These values are for design guidance only.
Consult Application Note AN826 “Crystal
Oscillator Basics and Crystal Selection for
rfPIC
for further information on Crystal/Capacitor
Selection.
INTCON
TMR1H
T1CON
TMR1L
Name
x = unknown, u = unchanged, - = unimplemented read as ‘0’. Shaded cells are not used by the Timer1 module.
PIR1
PIE1
®
CAPACITOR SELECTION FOR
THE TIMER1 OSCILLATOR
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
and PICmicro
Holding Register for the Least Significant Byte of the 16-bit TMR1 Register
Holding Register for the Most Significant Byte of the 16-bit TMR1 Register
EEIF
EEIE
Bit 7
GIE
—
15 pF
C1
CMIE
CMIF
Bit 6
PEIE
—
®
Devices” (DS00826)
T1CKPS1
RCIE
RCIF
Bit 5
T0IE
15 pF
C2
T1CKPS0
INTE
TXIE
Bit 4
TXIF
PIC16F627A/628A/648A
T1OSCEN
RBIE
Bit 3
—
—
7.5
If the CCP1 module is configured in Compare mode to
generate a “special event trigger” (CCP1M<3:0> =
1011), this signal will reset Timer1.
Timer1 must be configured for either timer or
Synchronized Counter mode to take advantage of this
feature. If Timer1 is running in Asynchronous Counter
mode, this Reset operation may not work.
In the event that a write to Timer1 coincides with a
special event trigger from CCP1, the write will take
precedence.
In this mode of operation, the CCPRxH:CCPRxL
register pair effectively becomes the period register for
Timer1.
7.6
TMR1H and TMR1L registers are not reset to 00h on
a POR or any other Reset except by the CCP1 special
event triggers (see Section 9.2.4 “Special Event
Trigger”).
T1CON register is reset to 00h on a Power-on Reset or
a Brown-out Reset, which shuts off the timer and
leaves a 1:1 prescale. In all other Resets, the register
is unaffected.
7.7
The prescaler counter is cleared on writes to the
TMR1H or TMR1L registers.
Note:
T1SYNC
CCP1IE
CCP1IF
Bit 2
T0IF
Resetting Timer1 Using a CCP
Trigger Output
Resetting Timer1 Register Pair
(TMR1H, TMR1L)
Timer1 Prescaler
The special event triggers from the CCP1
module will not set interrupt flag bit
TMR1IF (PIR1<0>).
TMR1CS
TMR2IF
TMR2IE
Bit 1
INTF
TMR1ON
TMR1IE
TMR1IF
RBIF
Bit 0
0000 000x
0000 -000
0000 -000
xxxx xxxx
xxxx xxxx
--00 0000
Value on
POR
DS40044D-page 51
0000 000u
0000 -000
0000 -000
uuuu uuuu
uuuu uuuu
--uu uuuu
Value on
all other
Resets