PIC16F887-E/P Microchip Technology Inc., PIC16F887-E/P Datasheet - Page 104

• Manufacturer Part Number: PIC16F887-E/P
• Description: 40 PIN, 14KB FLASH, 368 RAM, 36 I/O, PDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F887-E/P

• A/d Inputs: 14-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Frequency: 20 MHz
• Input Output: 35
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 14K Bytes
• Ram Size: 368 Bytes
• Resistance, Drain To Source On: Bytes
• Serial Interface: MSSP or EUSART
• 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

PIC16F882/883/884/886/887
9.1.6
The 10-bit A/D conversion result can be supplied in two
formats, left justified or right justified. The ADFM bit of
the ADCON0 register controls the output format.
Figure 9-3 shows the two output formats.
FIGURE 9-3:
9.2
9.2.1
To enable the ADC module, the ADON bit of the
ADCON0 register must be set to a ‘1’. Setting the GO/
DONE bit of the ADCON0 register to a ‘1’ will start the
Analog-to-Digital conversion.
9.2.2
When the conversion is complete, the ADC module will:
• Clear the GO/DONE bit
• Set the ADIF flag bit
• Update the ADRESH:ADRESL registers with new
9.2.3
If a conversion must be terminated before completion,
the GO/DONE bit can be cleared in software. The
ADRESH:ADRESL registers will not be updated with
the partially complete Analog-to-Digital conversion
sample. Instead, the ADRESH:ADRESL register pair
will retain the value of the previous conversion. Addi-
tionally, a 2 T
sition can be initiated. Following this delay, an input
acquisition is automatically started on the selected
channel.
DS41291E-page 102
Note:
conversion result
Note:
(ADFM = 0)
(ADFM = 1)
ADC Operation
RESULT FORMATTING
STARTING A CONVERSION
The GO/DONE bit should not be set in the
same instruction that turns on the ADC.
Refer to Section 9.2.6 “A/D Conversion
Procedure”.
COMPLETION OF A CONVERSION
TERMINATING A CONVERSION
A device Reset forces all registers to their
Reset state. Thus, the ADC module is
turned off and any pending conversion is
terminated.
AD
delay is required before another acqui-
10-BIT A/D CONVERSION RESULT FORMAT
MSB
bit 7
bit 7
Unimplemented: Read as ‘0’
ADRESH
10-bit A/D Result
MSB
bit 0
bit 0
9.2.4
The ADC module can operate during Sleep. This
requires the ADC clock source to be set to the F
option. When the F
ADC waits one additional instruction before starting the
conversion. This allows the SLEEP instruction to be
executed, which can reduce system noise during the
conversion. If the ADC interrupt is enabled, the device
will wake-up from Sleep when the conversion
completes. If the ADC interrupt is disabled, the ADC
module is turned off after the conversion completes,
although the ADON bit remains set.
When the ADC clock source is something other than
F
sion to be aborted and the ADC module is turned off,
although the ADON bit remains set.
9.2.5
The ECCP Special Event Trigger allows periodic ADC
measurements without software intervention. When
this trigger occurs, the GO/DONE bit is set by hardware
and the Timer1 counter resets to zero.
Using the Special Event Trigger does not assure proper
ADC timing. It is the user’s responsibility to ensure that
the ADC timing requirements are met.
See Section 11.0 “Capture/Compare/PWM Modules
(CCP1 and CCP2)” for more information.
RC
, a SLEEP instruction causes the present conver-
bit 7
bit 7
ADC OPERATION DURING SLEEP
SPECIAL EVENT TRIGGER
10-bit A/D Result
LSB
RC
Unimplemented: Read as ‘0’
© 2008 Microchip Technology Inc.
clock source is selected, the
ADRESL
bit 0
LSB
bit 0
RC