PIC16F785-I/SO Microchip Technology, PIC16F785-I/SO Datasheet - Page 42

• 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

PIC16F785
4.3
PORTB is a 4-bit wide, bidirectional port. The
corresponding data direction register is TRISB
(Register 4-6). Setting a TRISB bit (= 1) will make the
corresponding PORTB pin an input (i.e., put the
corresponding output driver in a High-impedance
mode). Clearing a TRISB bit (= 0) will make the
corresponding PORTB pin an output (i.e., put the
contents of the output latch on the selected pin).
Example 4-2 shows how to initialize PORTB.
Reading the PORTB register (Register 4-5) 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.
Pin RB6 is an open drain output. All other PORTB pins
have full CMOS output drivers.
REGISTER 4-5:
REGISTER 4-6:
DS41249A-page 40
PORTB and TRISB Registers
bit 7-4:
bit 3-0:
bit 7-4:
bit 3-0
PORTB — PORTB REGISTER (ADDRESS: 06h, 106h)
TRISB — PORTB TRISTATE REGISTER (ADDRESS: 86h, 186h)
RB<7:4>: PORTB General Purpose I/O Pin bits
1 = Port pin is > V
0 = Port pin is < V
Unimplemented: Read as “0”
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 12-2 on page 80).
TRISB<7:4>: PORTB Tri-State Control bits
1 = PORTB pin configured as an input (tri-stated)
0 = PORTB pin configured as an output
Unimplemented: Read as “0”
bit 7
Legend:
R = Readable bit
- n = Value at POR
bit 7
Legend:
R = Readable bit
- n = Value at POR
TRISB7
R/W-x
R/W-1
RB7
TRISB6
R/W-x
R/W-1
RB6
IH
IL
R/W-x
TRISB5
R/W-1
RB5
Preliminary
W = Writable bit
‘1’ = Bit is set
W = Writable bit
‘1’ = Bit is set
(1)
R/W-x
TRISB4
R/W-1
RB4
The TRISB register controls the direction of the
PORTB pins, even when they are being used as
analog inputs. The user must ensure the bits in the
TRISB register are maintained set when using them as
analog inputs. I/O pins configured as analog input
always read ‘0’.
EXAMPLE 4-2:
BCF
BCF
CLRF
BSF
BCF
BCF
MOVLW
MOVWF
BCF
Note:
(1)
STATUS,RP0
STATUS,RP1
PORTB
STATUS,RP0
ANSEL1,2
ANSEL1,3
30h
TRISB
STATUS,RP0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
U-0
U-0
—
—
The ANSEL1 (93h) register must be initial-
ized to configure an analog channel as a
digital input. Pins configured as analog
inputs will read ‘0’.
INITIALIZING PORTB
U-0
U-0
—
—
 2004 Microchip Technology Inc.
;Bank 0
;
;Init PORTB
;Bank 1
;digital I/O - RB4
;digital I/O - RB5
;Set RB<5:4> as inputs
;and set RB<7:6>
;as outputs
;Bank 0
x = Bit is unknown
x = Bit is unknown
U-0
U-0
—
—
U-0
U-0
—
—
bit 0
bit 0