PIC16C712-20/P Microchip Technology, PIC16C712-20/P Datasheet - Page 40

• Manufacturer Part Number: PIC16C712-20/P
• Description: IC MCU OTP 1KX14 A/D PWM 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C712-20/P

• Core Size: 8-Bit
• Program Memory Size: 1.75KB (1K x 14)
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Core Processor: PIC
• Speed: 20MHz
• Number Of I /o: 13
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 4x8b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 18-DIP (0.300", 7.62mm)
• Controller Family/series: PIC16C
• No. Of I/o's: 13
• Ram Memory Size: 128Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC16C712/716
7.1
In Capture mode, CCPR1H:CCPR1L captures the
16-bit value of the TMR1 register when an event occurs
on pin RB3/CCP1. An event is defined as:
• every falling edge
• every rising edge
• every 4th rising edge
• every 16th rising edge
An event is selected by control bits CCP1M3:CCP1M0
(CCP1CON<3:0>). When a capture is made, the inter-
rupt request flag bit CCP1IF (PIR1<2>) is set. It must
be cleared in software. If another capture occurs before
the value in register CCPR1 is read, the old captured
value will be lost.
FIGURE 7-3:
7.1.1
In Capture mode, the CCP output must be disabled by
setting the TRISCCP<2> bit.
7.1.2
Timer1 must be running in timer mode or synchronized
counter mode for the CCP module to use the capture
feature. In asynchronous counter mode, the capture
operation may not work.
7.1.3
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep bit
CCP1IE (PIE1<2>) clear to avoid false interrupts and
should clear the flag bit CCP1IF following any such
change in operating mode.
DS41106A-page 40
RB3/CCP1
Pin
Note:
Capture Mode
CCP PIN CONFIGURATION
TIMER1 MODE SELECTION
SOFTWARE INTERRUPT
If the RB3/CCP1 is configured as an output
by clearing the TRISCCP<2> bit, a write to
the DCCP bit can cause a capture condi-
tion.
edge detect
Q’s
Prescaler
1, 4, 16
and
CCP1CON<3:0>
CAPTURE MODE OPERATION
BLOCK DIAGRAM
Set flag bit CCP1IF
(PIR1<2>)
Capture
Enable
CCPR1H
TMR1H
CCPR1L
TMR1L
Preliminary
7.1.4
There are four prescaler settings, specified by bits
CCP1M3:CCP1M0. Whenever the CCP module is
turned off, or the CCP module is not in capture mode,
the prescaler counter is cleared. This means that any
reset will clear the prescaler counter.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared, therefore the first capture may be from
a non-zero prescaler. Example 7-1 shows the recom-
mended method for switching between capture pres-
calers. This example also clears the prescaler counter
and will not generate the “false” interrupt.
EXAMPLE 7-1:
CLRF
MOVLW
MOVWF
CCP1CON
NEW_CAPT_PS
CCP1CON
CCP PRESCALER
CHANGING BETWEEN
CAPTURE PRESCALERS
;Turn CCP module off
;Load the W reg with
; the new prescaler
; mode value and CCP ON
;Load CCP1CON with this
; value
1999 Microchip Technology Inc.