PIC16C432-E/SS Microchip Technology, PIC16C432-E/SS Datasheet - Page 19

• Manufacturer Part Number: PIC16C432-E/SS
• Description: IC MCU CMOS 8BIT 20MHZ 2K 20SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C432-E/SS

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: LIN (Local Interconnect Network)
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 12
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 20-SSOP
• For Use With: XLT20SS-1 - SOCKET TRANSITION 18DIP 20SSOPAC164307 - MODULE SKT FOR PM3 28SSOPAC164029 - MODULE SKT PROMATEII 20DIP/SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

4.0
The PIC16C432 parts have two ports, PORTA and
PORTB. 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.
4.1
PORTA is a 5-bit wide latch. RA4 is a Schmitt Trigger
input and an open drain output. Port RA4 is multiplexed
with the T0CKI clock input. All other RA port pins have
Schmitt Trigger input levels and full CMOS output driv-
ers. All pins have data direction bits (TRIS registers),
which can configure these pins as input or output.
A ’1’ in the TRISA register puts the corresponding out-
put driver in a Hi-impedance mode. A ’0’ in the TRISA
register puts the contents of the output latch on the
selected pin(s).
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. So a write
to a port implies that the port pins are first read, then this
value is modified and written to the port data latch.
The PORTA pins are multiplexed with comparator and
voltage reference functions. The operation of these
pins are selected by control bits in the CMCON
(Comparator Control Register) register and the
VRCON (Voltage Reference Control Register) register.
When selected as a comparator input, these pins will
read as ’0’s.
FIGURE 4-1:
WR
TRISA
WR
PORTA
2002 Microchip Technology Inc.
Data
Bus
RD PORTA
I/O PORTS
PORTA and TRISA Registers
To Comparator
TRIS Latch
Data Latch
D
D
CK
CK
RD TRISA
Q
Q
Q
Q
BLOCK DIAGRAM OF RA0
PINS
Input Mode
Q
Schmitt Trigger
Analog
Input Buffer
EN
V
Vss
P
N
D
DD
V
DD
I/O Pin
Preliminary
TRISA controls the direction of the RA pins, even when
they are being used as comparator inputs. The user
must make sure to keep the pins configured as inputs
when using them as comparator inputs.
The RA2 pin will also function as the output for the volt-
age reference. When in this mode, the V
high impedance output. The user must configure
TRISA<2> bit as an input and use high impedance loads.
In one of the comparator modes defined by the
CMCON register, pins RA3 and RA4 become outputs
of the comparators. The TRISA<4:3> bits must be
cleared to enable outputs to use this function.
EXAMPLE 4-1:
CLRF
MOVLW
MOVWF
BSF
MOVLW
MOVWF
Note:
Note 1: BACT pin is an output and must be left
PORTA
0X07
CMCON
STATUS,
RP0
0x1F
TRISA
On RESET, the TRISA register is set to all
inputs. The digital inputs are disabled and
the comparator inputs are forced to
ground, to reduce excess current con-
sumption.
open if unused.
;Initialize PORTA by setting
;output data latches
;Turn comparators off and
;enable pins for I/O
;functions
;Select Bank1
;Value used to initialize
;data direction
;Set RA<4:0> as inputs
;TRISA<7:5> are always
;read as ’0’.
INITIALIZING PORTA
PIC16C432
DS41140B-page 17
REF
pin is a very