PIC16C554-04E/P Microchip Technology, PIC16C554-04E/P Datasheet - Page 25

• Manufacturer Part Number: PIC16C554-04E/P
• Description: IC MCU OTP 512X14 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C554-04E/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Size: 896B (512 x 14)
• Program Memory Type: OTP
• Ram Size: 80 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 18-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -

5.0
The PIC16C554 and PIC16C558 have two ports,
PORTA and PORTB. The PIC16C557 has three ports,
PORTA, PORTB and PORTC.
5.1
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.
FIGURE 5-1:
 2002 Microchip Technology Inc.
WR
PORTA
Data
Bus
WR
TRISA
RD PORTA
Note 1: On RESET, the TRISA register is set to all
I/O PORTS
PORTA and TRISA Registers
Data Latch
TRIS Latch
inputs.
D
CK
D
CK
Q
Q
Q
Q
RD TRISA
BLOCK DIAGRAM OF
PORT PINS RA<3:0>
Q
Schmitt
Trigger
input
buffer
EN
D
V
V
P
N
SS
DD
V
V
DD
SS
I/O pin
Preliminary
FIGURE 5-2:
Data
bus
WR
TRISA
WR
PORTA
RD PORTA
TMR0 clock input
TRISA Latch
Data Latch
D
D
CK
CK
RD TRISA
Q
Q
Q
Q
BLOCK DIAGRAM OF RA4
PIN
PIC16C55X
Q
Schmitt
Trigger
input
buffer
EN
EN
D
DS40143D-page 23
V
N
SS
V
SS
I/O pin
(1)