PIC16C770-I/SO Microchip Technology, PIC16C770-I/SO Datasheet - Page 59

• Manufacturer Part Number: PIC16C770-I/SO
• Description: IC MCU OTP 2KX14 A/D PWM 20-SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C770-I/SO

• Core Size: 8-Bit
• Program Memory Size: 3.5KB (2K x 14)
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI
• Number Of I /o: 15
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 6x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SOIC (7.5mm Width)
• Controller Family/series: PIC16C
• No. Of I/o's: 16
• Ram Memory Size: 256Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMINGAC164028 - MODULE SKT PROMATEII 20SOIC/DIP309-1013 - ADAPTER 20-SOIC TO 20-DIP309-1012 - ADAPTER 20-SOIC TO 20-DIP
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: PIC16C770I/SO

8.3.2
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
CCPR1L and CCP1CON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPR1H until after a match between PR2 and TMR2
occurs (i.e., the period is complete). In PWM mode,
CCPR1H is a read-only register.
The CCPR1H register and a 2-bit internal latch are
used to double buffer the PWM duty cycle. This double
buffering is essential for glitchless PWM operation.
When the CCPR1H and 2-bit latch match TMR2 con-
catenated with an internal 2-bit Q clock or 2 bits of the
TMR2 prescaler, the CCP1 pin is cleared.
Maximum PWM resolution (bits) for a given PWM fre-
quency:
8.3.3
The PWM1M1 bits in the CCP1CON register allows
one of the following configurations:
• Single output
• Half-Bridge output
• Full-Bridge output, Forward mode
• Full-Bridge output, Reverse mode
In the Single Output mode, the RB3/CCP1/P1A pin is
used as the PWM output. Since the CCP1 output is
multiplexed with the PORTB<3> data latch, the
TRISB<3> bit must be cleared to make the CCP1 pin
an output.
2002 Microchip Technology Inc.
Note:
PWM duty cycle
PWM DUTY CYCLE
If the PWM duty cycle value is longer than
the PWM period, the CCP1 pin will not be
cleared.
PWM OUTPUT CONFIGURATIONS
=
log
-----------------------------bits
= (CCPR1L:CCP1CON<5:4>) •
log
T
OSC
---------------
F
F
PWM
OSC
2
• (TMR2 prescale value)
FIGURE 8-4:
FIGURE 8-5:
In the Half-Bridge Output mode, two pins are used as
outputs. The RB3/CCP1/P1A pin has the PWM output
signal, while the RB5/SDO/P1B pin has the comple-
mentary PWM output signal. This mode can be used
for half-bridge applications, as shown on Figure 8-7, or
for full-bridge applications, where four power switches
are being modulated with two PWM signal.
Since the P1A and P1B outputs are multiplexed with
the PORTB<3> and PORTB<5> data latches, the
TRISB<3> and TRISB<5> bits must be cleared to con-
figure P1A and P1B as outputs.
In Half-Bridge Output mode, the programmable dead-
band delay can be used to prevent shoot-through cur-
rent in bridge power devices. See Section 8.3.5 for
more details of the deadband delay operations.
Note 1: At this time, the TMR2 register is equal to the PR2 register.
CCP1
PIC16C717/770/771
PIC16C717/770/771
PIC16C717/770/771
2: Output signal is shown as asserted high.
(2)
(1)
CCP1
Duty Cycle
CCP1
Period
SINGLE PWM OUTPUT
EXAMPLE OF SINGLE
OUTPUT APPLICATION
R
V+
O
A
D
L
(1)
C
DS41120B-page 57
Vout
Using PWM to
Drive a Power
Load
Using PWM as
a D/A Converter