PIC16F628A-I/SO Microchip Technology, PIC16F628A-I/SO Datasheet - Page 65

• Manufacturer Part Number: PIC16F628A-I/SO
• Description: IC MCU FLASH 2KX14 EEPROM 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F628A-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 3.5KB (2K x 14)
• Package / Case: 18-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Eeprom Size: 128 x 8
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 224 B
• Interface Type: SCI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT18SO-1 - SOCKET TRANSITION 18SOIC 300MILI3DBF648 - BOARD DAUGHTER ICEPIC3AC162053 - HEADER INTERFACE ICD,ICD2 18DIPAC164010 - MODULE SKT PROMATEII DIP/SOIC
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The code example in Example 10-1 depicts the steps
required to configure the Comparator module. RA3 and
RA4 are configured as digital output. RA0 and RA1 are
configured as the V- inputs and RA2 as the V+ input to
both comparators.
EXAMPLE 10-1:
10.2
A single comparator is shown in Figure 10-2 along with
the relationship between the analog input levels and
the digital output. When the analog input at V
than the analog input V
is a digital low level. When the analog input at V
greater than the analog input V
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 10-2 represent
the uncertainty due to input offsets and response time.
See Table 17-2 for Common Mode Voltage.
10.3
An external or internal reference signal may be used
depending on the comparator Operating mode. The
analog signal that is present at V
signal at V
is adjusted accordingly (Figure 10-2).
 2004 Microchip Technology Inc.
FLAG_REG
CLRF
CLRF
MOVF
ANDLW
IORWF
MOVLW
MOVWF
BSF
MOVLW
MOVWF
BCF
CALL
MOVF
BCF
BSF
BSF
BCF
BSF
BSF
Comparator Operation
Comparator Reference
FLAG_REG
PORTA
CMCON, W
0xC0
FLAG_REG,F ;Store bits in flag register
0x03
CMCON
STATUS,RP0 ;Select Bank1
0x07
TRISA
STATUS,RP0 ;Select Bank 0
DELAY10
CMCON,F
PIR1,CMIF
STATUS,RP0 ;Select Bank 1
PIE1,CMIE
STATUS,RP0 ;Select Bank 0
INTCON,PEIE ;Enable peripheral interrupts
INTCON,GIE ;Global interrupt enable
IN
+, and the digital output of the comparator
EQU
;Init flag register
;Init PORTA
;Load comparator bits
;Mask comparator bits
;Init comparator mode
;CM<2:0> = 011
;Initialize data direction
;Set RA<2:0> as inputs
;RA<4:3> as outputs
;TRISA<7:5> always read ‘0’
;10µs delay
;Read CMCON to end change
;condition
;Clear pending interrupts
;Enable comparator interrupts
COMPARATOR MODULE
INITIALIZING
IN
-, the output of the comparator
IN
IN
0X20
- is compared to the
-, the output of the
IN
+ is less
IN
+ is
Preliminary
PIC16F627A/628A/648A
FIGURE 10-2:
10.3.1
When external voltage references are used, the
Comparator module can be configured to have the
comparators operate from the same or different
reference sources. However, threshold detector
applications may require the same reference. The
reference signal must be between V
can be applied to either pin of the comparator(s).
10.3.2
The Comparator module also allows the selection of
an internally generated voltage reference for the
Module", contains a detailed description of the
The internal reference signal is used when the com-
parators are in mode CM<2:0>=010 (Figure 10-1). In
this mode, the internal voltage reference is applied to
the V
10.4
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output is to have a valid level. If the internal
reference is changed, the maximum delay of the inter-
nal voltage reference must be considered when using
the comparator outputs. Otherwise, the maximum
delay of the comparators should be used (Table 17-2).
comparators. Section 11.0 "Voltage Reference
Voltage Reference Module that provides this signal.
V
V
Result
IN
IN
-
+
IN
Vin+
Vin-
+ pin of both comparators.
Comparator Response Time
EXTERNAL REFERENCE SIGNAL
INTERNAL REFERENCE SIGNAL
–
+
SINGLE COMPARATOR
DS40044B-page 63
SS
Result
and V
DD
, and