PIC16F74-I/P Microchip Technology Inc., PIC16F74-I/P Datasheet - Page 52

• Manufacturer Part Number: PIC16F74-I/P
• Description: 40 PIN, 7 KB FLASH, 192 RAM, 33 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F74-I/P

• A/d Inputs: 8-Channel, 8-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 33
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 7K Bytes
• Ram Size: 192 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16F7X
6.5
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>). The oscilla-
tor is a low power oscillator rated up to 200 kHz. It will
continue to run during SLEEP. It is primarily intended
for use with a 32 kHz crystal. Table 6-1 shows the
capacitor selection for the Timer1 oscillator.
The Timer1 oscillator is identical to the LP oscillator.
The user must provide a software time delay to ensure
proper oscillator start-up.
6.6
If the CCP1 or CCP2 module is configured in Compare
mode
(CCP1M3:CCP1M0 = ‘1011’), this signal will reset
Timer1.
Timer1 must be configured for either Timer or Synchro-
nized 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 spe-
cial event trigger from CCP1 or CCP2, the write will
take precedence.
In this mode of operation, the CCPRxH:CCPRxL regis-
ter pair effectively becomes the period register for
Timer1.
6.7
TMR1H and TMR1L registers are not reset to 00h on a
POR, or any other RESET, except by the CCP1 and
CCP2 special event triggers.
TABLE 6-2:
DS30325B-page 50
Address
0Bh,8Bh,
10Bh,18Bh
0Ch
8Ch
0Eh
0Fh
10h
Legend:
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F73/76; always maintain these bits clear.
Note:
to
Timer1 Oscillator
Resetting Timer1 using a CCP
Trigger Output
Resetting of Timer1 Register Pair
(TMR1H, TMR1L)
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.
The special event triggers from the CCP1
and CCP2 modules will not set interrupt
flag bit TMR1IF (PIR1<0>).
INTCON
PIR1
PIE1
TMR1L
TMR1H Holding register for the Most Significant Byte of the 16-bit TMR1 Register
T1CON
generate
Name
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Holding register for the Least Significant Byte of the 16-bit TMR1 Register
PSPIF
PSPIE
Bit 7
GIE
—
a
(1)
(1)
“special
PEIE
ADIF
ADIE
Bit 6
—
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu
TMR0IE
event
RCIF
RCIE
Bit 5
trigger”
INTE
Bit 4
TXIF
TXIE
SSPIE
SSPIF
RBIE
Bit 3
TABLE 6-1:
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.
6.8
The prescaler counter is cleared on writes to the
TMR1H or TMR1L registers.
Capacitor values are for design guidance only.
These capacitors were tested with the crystals listed
below for basic start-up and operation. These values
were not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
V
See the notes (below) table for additional information.
32.768 kHz
100 kHz
200 kHz
Note 1: Higher capacitance increases the stability
Osc Type
DD
TMR0IF
CCP1IE TMR2IE
CCP1IF
LP
and temperature range for the application.
Bit 2
2: Since each resonator/crystal has its own
Timer1 Prescaler
of the oscillator, but also increases the
start-up time.
characteristics, the user should consult the
resonator/crystal manufacturer for appro-
priate values of external components.
Commonly Used Crystals:
TMR2IF
Frequency
Bit 1
INTF
100 kHz
200 kHz
32 kHz
CAPACITOR SELECTION FOR
THE TIMER1 OSCILLATOR
Epson C-001R32.768K-A
Epson C-2 100.00 KC-P
STD XTL 200.000 kHz
TMR1IF 0000 0000 0000 0000
TMR1IE 0000 0000 0000 0000
 2002 Microchip Technology Inc.
Bit 0
RBIF
OSC1
47 pF
33 pF
15 pF
Capacitors Used:
0000 000x 0000 000u
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
Value on:
POR,
BOR
OSC2
47 pF
33 pF
15 pF
Value on
RESETS
all other