PIC14000-04/SS Microchip Technology, PIC14000-04/SS Datasheet - Page 35

• Manufacturer Part Number: PIC14000-04/SS
• Description: IC MCU OTP 4KX14 A/D 28SSOP
• Manufacturer: Microchip Technology
• Series: PIC® 14r

Specifications of PIC14000-04/SS

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 20
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: Slope A/D
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Processor Series: PIC14000
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: 0 C
• On-chip Adc: 14 bit
• For Use With: 309-1025 - ADAPTER 28-SSOP TO 28-DIPXLT28SS-1 - SOCKET TRANSITION ICE 28SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

If the CMBOE bit (CMCON<5>) is set, the RD3/REFB
pin becomes the programmable reference B output
and pin RD2/CMPB becomes the comparator B output.
PORTD<1:0> also serve multiple functions. These pins
act as the I
is enabled.
The TRISD register controls the direction of the Port D
pins.
corresponding port pin as an input. Upon reset, this
register sets to FFh, meaning all PORTD pins are ini-
tially inputs. The data register should be initialized prior
to configuring the port as outputs.
Unused inputs should not be left floating to avoid
leakage currents. All pins have input protection diodes
to V
EXAMPLE 5-3:
CLRF
BSF
MOVLW 0xFF
MOVWF TRISD
1996 Microchip Technology Inc.
Note:
DD
A
and V
PORTD
STATUS, RP0
2
Setting CMBOE changes the definition of
RD3/REFB and RD2/CMPB, bypassing
the PORTD data and TRISD register set-
tings.
‘1’
C data and clock lines when the I
SS
.
in
each
INITIALIZING PORTD
; Initialize PORTD data
;
;
;
; Select Bank1
; Value used to initialize
; data direction
; Set RD<7:0> as inputs
location
latches before setting
the data direction
register
configures
2
C module
Preliminary
the
5.4
5.4.1
Reading the port register reads the values of the port
pins. Writing to the port register writes the value to the
port latch. Some instructions operate internally as
read-modify-write. The BCF and BSF instructions, for
example, read the register into the CPU, execute the bit
operation, and write the result back to the register.
Caution must be used when these instructions are
applied to a port with both inputs and outputs defined.
For example, a BSF operation on bit5 of PORTC will
cause all eight bits of PORTC to be read into the CPU.
Then the BSF operation takes place on bit5 and
PORTC is written to the output latches. If another bit of
PORTC is used as a bi-directional I/O pin (say bit0) and
it is defined as an input at this time, the input signal
present on the pin itself would be read into the CPU
and re-written to the data latch of this particular pin,
overwriting the previous content. As long as the pin
stays in the input mode, no problem occurs. However,
if bit0 is switched into output mode later on, the content
of the data latch may now be unknown.
A pin actively outputting a LOW or HIGH should not be
driven from external devices at the same time in order
to change the level on this pin (“wire-or”, “wire-and”).
The resulting high output currents may damage the
chip.
Example 5-4 shows the effect of two sequential read
modify write instructions (ex. BCF, BSF, etc.) on an I/O
Port.
EXAMPLE 5-4:
;
;
;
;
;
;
;
;
;
; Note that the user may have expected the pin
; values to be 00pp pppp. The 2nd BCF caused
; RC7 to be latched as the pin value (High).
Initial PORT settings:
PORTC<7:6> have external pull-up and are not
connected to other circuitry
BCF PORTC, 7
BCF PORTC, 6
BSF STATUS,RP0
BCF TRISC, 7
BCF TRISC, 6
I/O Programming Considerations
BI-DIRECTIONAL I/O PORTS
READ MODIFY WRITE
INSTRUCTIONS ON AN
I/O PORT
; 01pp pppp
; 10pp pppp
;
; 10pp pppp
; 10pp pppp
PIC14000
PORTC<7:4> Inputs
PORTC<3:0> Outputs
PORT latch PORT pins
----------
DS40122B-page 35
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11pp pppp
11pp pppp
11pp pppp
10pp pppp