PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 256

• Manufacturer Part Number: PIC16F877-20/P
• Description: IC MCU FLASH 8KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-20/P

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• 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: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• 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, Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
16.3
16.3.1
DS31016A-page 16-6
SPI is a trademark of Motorola Corporations.
Operation
SPI™ Mode
The SPI mode allows 8-bits of data to be synchronously transmitted and received simulta-
neously. To accomplish communication, typically three pins are used:
• Serial Data Out (SDO)
• Serial Data In (SDI)
• Serial Clock (SCK)
Additionally a fourth pin may be used when in a slave mode of operation:
• Slave Select (SS)
When initializing the SPI, several options need to be specified. This is done by programming the
appropriate control bits in the SSPCON register (SSPCON<5:0>). These control bits allow the
following to be specified:
• Master Mode (SCK is the clock output)
• Slave Mode (SCK is the clock input)
• Clock Polarity (Output/Input data on the Rising/Falling edge of SCK)
• Clock Rate (Master mode only)
• Slave Select Mode (Slave mode only)
Figure 16-1
Figure 16-1: SSP Block Diagram (SPI Mode)
shows the block diagram of the SSP module, when in SPI mode.
SDI
SDO
SS
SCK
Read
SS Control
TRIS bit of SCK pin
Select
Edge
Enable
bit0
Select
Edge
SSPBUF reg
SSPM3:SSPM0
SSPSR reg
Clock Select
4
2
shift clock
Write
Prescaler
4, 16, 64
data bus
Internal
TMR2 output
1997 Microchip Technology Inc.
T
CY
2