PIC16F785-I/SO Microchip Technology, PIC16F785-I/SO Datasheet - Page 35

• Manufacturer Part Number: PIC16F785-I/SO
• Description: IC PIC MCU FLASH 2KX14 20SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F785-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 3.5KB (2K x 14)
• Package / Case: 20-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 17
• Eeprom Size: 256 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: RS- 232/USB
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 17
• 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, DV164120, DM163029
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT20SO1-1 - SOCKET TRANS ICE 20DIP TO 20SOICXLT18SO-1 - SOCKET TRANSITION 18SOIC 300MILAC162060 - HEADER INTRFC MPLAB ICD2 20PINAC164039 - MODULE SKT PROMATE II 20DIP/SOIC
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.0
There are seventeen general purpose I/O pins and one
input only pin available. Depending on which peripher-
als are enabled, some or all of the pins may not be
available as general purpose I/O. In general, when a
peripheral is enabled, the associated pin may not be
used as a general purpose I/O pin.
4.1
PORTA is a 6-bit wide, bidirectional port. The
corresponding data direction register is TRISA
(Register 4-2). Setting a TRISA bit (= 1) will make the
corresponding PORTA pin an input (i.e., put the
corresponding output driver in a High-impedance
mode). Clearing a TRISA bit (= 0) will make the
corresponding PORTA pin an output (i.e., put the
contents of the output latch on the selected pin). The
exception is RA3, which is input only and its TRIS bit
will always read as ‘1’. Example 4-1 shows how to
initialize PORTA.
Reading the PORTA register (Register 4-1) reads the
status of the pins, whereas writing to it will write to the
port latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read; this value is modified and then writ-
ten to the port data latch. RA3 reads ‘0’ when
MCLRE = 1.
REGISTER 4-1:
Note:
 2004 Microchip Technology Inc.
I/O PORTS
PORTA and TRISA Registers
bit 7-6:
bit 5-0:
Additional information on I/O ports may be
found
Reference Manual (DS33023).
in
PORTA — PORTA REGISTER (ADDRESS: 05h, 105h)
bit 7
Unimplemented: Read as ‘0’
RA<5:0>: PORTA I/O pin
1 = Port pin is >V
0 = Port pin is <V
Note 1: Data latches are unknown after a POR, but each port bit reads ‘0’ when the corre-
sponding analog select bit is ‘1’ (see Register 12-1 on page 80).
Legend:
R = Readable bit
- n = Value at POR
the
U-0
—
PICmicro
U-0
®
—
IH
IL
Mid-Range
R/W-x
RA5
W = Writable bit
‘1’ = Bit is set
Preliminary
R/W-x
RA4
The TRISA register controls the direction of the
PORTA pins, even when they are being used as analog
inputs. The user must ensure the bits in the TRISA
register are maintained set when using them as analog
inputs. I/O pins configured as analog inputs always
read ‘0’.
When RA1 is configured as a voltage reference output,
the RA1 digital output driver will automatically be dis-
abled while not affecting the TRISA<1> value.
EXAMPLE 4-1:
(1)
Note:
BCF
BCF
CLRF
MOVLW
ANDWF
BSF
MOVLW
MOVWF
BCF
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-x
STATUS,RP0
STATUS,RP1
PORTA
F8h
ANSEL0,f
STATUS,RP0
0Ch
TRISA
STATUS,RP0
RA3
The ANSEL0 (91h) register must be initial-
ized to configure an analog channel as a
digital input. Pins configured as analog
inputs will read ‘0’.
R/W-x
INITIALIZING PORTA
RA2
;Bank 0
;
;Init PORTA
;Set RA<2:0> to
; digital I/O
;Bank 1
;Set RA<3:2> as inputs
; and set RA<5:4,1:0>
; as outputs
;Bank 0
(1)
PIC16F785
x = Bit is unknown
R/W-x
RA1
(1)
DS41249A-page 33
R/W-x
RA0
bit 0
(1)