PIC16F88-I/SO Microchip Technology Inc., PIC16F88-I/SO Datasheet - Page 53

• Manufacturer Part Number: PIC16F88-I/SO
• Description: 18 PIN, 7 KB FLASH, 368 RAM, 16 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F88-I/SO

• A/d Inputs: 7-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 16
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 18-pin SOIC
• Programmable Memory: 7K Bytes
• Ram Size: 368 Bytes
• 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

5.0
Some pins for these I/O ports are multiplexed with an
alternate function for the peripheral features on the
device. In general, when a peripheral is enabled, that
pin may not be used as a general purpose I/O pin.
Additional information on I/O ports may be found in the
“PICmicro
(DS33023).
5.1
PORTA is an 8-bit wide, bidirectional port. The corre-
sponding data direction register is TRISA. 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).
Reading the PORTA register, 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 written to the port
data latch.
TABLE 5-1:
 2005 Microchip Technology Inc.
RA0/AN0
RA1/AN1
RA2/AN2/CV
RA3/AN3/V
RA4/AN4
RA5/MCLR/V
RA6/OSC2/CLKO
RA7/OSC1/CLKI
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1:
Note:
2:
I/O PORTS
PORTA and the TRISA Register
®
(2)
Mid-Range MCU Family Reference Manual”
This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.
PIC16F88 only.
On
PORTA<4:0> are configured as analog
inputs and read as ‘0’.
REF
/T0CKI/C2OUT
REF
PP
Name
+
(2)
/V
a
PORTA FUNCTIONS
/C1OUT
REF
Power-on
-
(2)
Reset,
Bit#
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
the
ST/CMOS
Buffer
TTL
TTL
TTL
TTL
ST
ST
ST
pins
(1)
Input/output or analog input.
Input/output or analog input.
Input/output, analog input, V
output.
Input/output, analog input, V
Input/output, analog input, TMR0 external input or
comparator output.
Input, Master Clear (Reset) or programming voltage input.
Input/output, connects to crystal or resonator, oscillator
output or 1/4 the frequency of OSC1 and denotes the
instruction cycle in RC mode.
Input/output, connects to crystal or resonator or oscillator
input.
Pin RA4 is multiplexed with the Timer0 module clock
input. On PIC16F88 devices, it is also multiplexed with
an analog input to become the RA4/AN4/T0CKI/
C2OUT pin. The RA4/AN4/T0CKI/C2OUT pin is a
Schmitt Trigger input and full CMOS output driver.
Pin RA5 is multiplexed with the Master Clear module
input. The RA5/MCLR/V
input.
Pin RA6 is multiplexed with the oscillator module input
and external oscillator output. Pin RA7 is multiplexed
with the oscillator module input and external oscillator
input. Pin RA6/OSC2/CLKO and pin RA7/OSC1/CLKI
are Schmitt Trigger inputs and full CMOS output drivers.
Pins RA<1:0> are multiplexed with analog inputs. Pins
RA<3:2> are multiplexed with analog inputs and com-
parator outputs. On PIC16F88 devices, pins RA<3:2>
are also multiplexed with the V
have TTL inputs and full CMOS output drivers.
EXAMPLE 5-1:
BANKSEL PORTA
CLRF
BANKSEL ANSEL
MOVLW
MOVWF
MOVLW
MOVWF
PORTA
0x00
ANSEL
0xFF
TRISA
Function
PIC16F87/88
REF-
REF+
INITIALIZING PORTA
; select bank of PORTA
; Initialize PORTA by
; clearing output
; data latches
; Select Bank of ANSEL
; Configure all pins
; as digital inputs
; Value used to
; initialize data
; direction
; Set RA<7:0> as inputs
PP
or comparator V
or comparator output.
pin is a Schmitt Trigger
REF
inputs. Pins RA<3:0>
DS30487C-page 51
REF