PIC16F877A-I/P Microchip Technology, PIC16F877A-I/P Datasheet - Page 51

• Manufacturer Part Number: PIC16F877A-I/P
• Description: IC MCU FLASH 8KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877A-I/P

• Program Memory Type: FLASH
• Program Memory Size: 14KB (8K x 14)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: CCP/I2C/MSSP/SPI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: PIC16F877AI/P

4.5
PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6
and RE2/CS/AN7) which are individually configurable
as inputs or outputs. These pins have Schmitt Trigger
input buffers.
The PORTE pins become the I/O control inputs for the
microprocessor port when bit PSPMODE (TRISE<4>) is
set. In this mode, the user must make certain that the
TRISE<2:0> bits are set and that the pins are configured
as digital inputs. Also, ensure that ADCON1 is config-
ured for digital I/O. In this mode, the input buffers are
TTL.
Register 4-1 shows the TRISE register which also
controls the Parallel Slave Port operation.
PORTE pins are multiplexed with analog inputs. When
selected for analog input, these pins will read as ‘0’s.
TRISE controls the direction of the RE pins, even when
they are being used as analog inputs. The user must
make sure to keep the pins configured as inputs when
using them as analog inputs.
TABLE 4-9:
 2003 Microchip Technology Inc.
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1:
Note:
Note:
Name
PORTE and TRISE Register
Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.
PORTE and TRISE are not implemented
on the 28-pin devices.
On a Power-on Reset, these pins are
configured as analog inputs and read as ‘0’.
Bit#
bit 0
bit 1
bit 2
PORTE FUNCTIONS
Buffer Type
ST/TTL
ST/TTL
ST/TTL
(1)
(1)
(1)
I/O port pin or read control input in Parallel Slave Port mode or analog input:
RD
1 = Idle
0 = Read operation. Contents of PORTD register are output to PORTD
I/O port pin or write control input in Parallel Slave Port mode or analog input:
WR
1 = Idle
0 = Write operation. Value of PORTD I/O pins is latched into PORTD
I/O port pin or chip select control input in Parallel Slave Port mode or analog input:
CS
1 = Device is not selected
0 = Device is selected
register (if chip selected).
I/O pins (if chip selected).
FIGURE 4-9:
Note 1: I/O pins have protection diodes to V
Data
Bus
WR
Port
WR
TRIS
RD
TRIS
RD Port
Function
TRIS Latch
Data Latch
D
D
CK
CK
Q
Q
PIC16F87XA
PORTE BLOCK DIAGRAM
(IN I/O PORT MODE)
Q
EN
EN
Schmitt
Trigger
Input
Buffer
D
DS39582B-page 49
DD
and V
I/O pin
SS
.
(1)