PIC18F2480_09 Datasheet, PDF (262/490 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology

PIC18F2480/2580/4480/4580
20.7 Use of the CCP1 Trigger
An A/D conversion can be started by the “Special Event
Trigger” of the ECCP1 module. This requires that the
ECCP1M<3:0> bits (ECCP1CON<3:0>) be pro-
grammed as ‘1011’ and that the A/D module is enabled
(ADON bit is set). When the trigger occurs, the
GO/DONE bit will be set, starting the A/D acquisition
and conversion and the Timer1 (or Timer3) counter will
be reset to zero. Timer1 (or Timer3) is reset to automat-
ically repeat the A/D acquisition period with minimal
software overhead (moving ADRESH/ADRESL to the
desired location). The appropriate analog input chan-
nel must be selected and the minimum acquisition
period is either timed by the user, or an appropriate
TACQ time selected before the “Special Event Trigger”
sets the GO/DONE bit (starts a conversion).
If the A/D module is not enabled (ADON is cleared), the
“Special Event Trigger” will be ignored by the A/D
module, but will still reset the Timer1 (or Timer3) coun-
ter.
TABLE 20-2: REGISTERS ASSOCIATED WITH A/D OPERATION
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE
IPR1
PSPIP
ADIP
RCIP
PIR1
PSPIF
ADIF
RCIF
PIE1
PSPIE
ADIE
RCIE
IPR2
OSCFIP CMIP
—
PIR2
OSCFIF CMIF
—
PIE2
OSCFIE CMIE
—
ADRESH A/D Result Register High Byte
ADRESL A/D Result Register Low Byte
INT0IE
TXIP
TXIF
TXIE
EEIP
EEIF
EEIE
RBIE TMR0IF INT0IF
RBIF
55
SSPIP CCP1IP TMR2IP TMR1IP
58
SSPIF CCP1IF TMR2IF TMR1IF
58
SSPIE CCP1IE TMR2IE TMR1IE
58
BCLIP HLVDIP TMR3IP ECCP1IP⁽⁵⁾ 57
BCLIF HLVDIF TMR3IF ECCP1IF⁽⁵⁾ 58
BCLIE HLVDIE TMR3IE ECCP1IE⁽⁵⁾ 58
56
56
ADCON0
—
—
CHS3
CHS2
CHS1 CHS0 GO/DONE ADON
56
ADCON1
—
—
VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0
56
ADCON2 ADFM
—
ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0
57
PORTA
RA7⁽²⁾
RA6⁽²⁾
RA5
RA4
RA3
RA2
RA1
RA0
58
TRISA TRISA7⁽²⁾ TRISA6⁽²⁾ PORTA Data Direction Register
58
PORTB Read PORTB pins, Write LATB Latch
58
TRISB PORTB Data Direction Register
58
LATB PORTB Output Data Latch
58
PORTE⁽⁴⁾
—
—
—
—
RE3⁽³⁾ Read PORTE pins, Write LATE⁽¹⁾
58
TRISE⁽⁴⁾
IBF
OBF
IBOV PSPMODE — PORTE Data Direction
58
LATE⁽⁴⁾
—
—
—
—
—
LATE2 LATE1 LATE0
58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: These bits are unimplemented on PIC18F2X80 devices; always maintain these bits clear.
2: These pins may be configured as port pins depending on the Oscillator mode selected.
3: RE3 port bit is available only as an input pin when the MCLRE Configuration bit is ‘0’.
4: These registers are not implemented on PIC18F2X80 devices.
5: These bits are available on PIC18F4X80 and reserved on PIC18F2X80 devices.
DS39637D-page 262
© 2009 Microchip Technology Inc.