PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 259

• 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

Section 16. BSSP
16
16.3.3
Typical Connection
Figure 16-2
shows a typical connection between two microcontrollers. The master controller
(Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both
shift registers on their programmed clock edge, and latched on the opposite edge of the clock.
Both processors should be programmed to same Clock Polarity (CKP), then both controllers
would send and receive data at the same time. Whether the data is meaningful (or dummy data)
depends on the application software. This leads to three scenarios for data transmission:
• Master sends data — Slave sends dummy data
• Master sends data — Slave sends data
• Master sends dummy data — Slave sends data
Figure 16-2: SPI Master/Slave Connection
SPI Master (SSPM3:SSPM0 = 00xxb)
SPI Slave (SSPM3:SSPM0 = 010xb)
SDO
SDI
Serial Input Buffer
Serial Input Buffer
(SSPBUF)
(SSPBUF)
SDI
SDO
Shift Register
Shift Register
(SSPSR)
(SSPSR)
LSb
MSb
MSb
LSb
Serial Clock
SCK
SCK
PROCESSOR 1
PROCESSOR 2
1997 Microchip Technology Inc.
DS31016A-page 16-9