PIC18F6680-I/L Microchip Technology, PIC18F6680-I/L Datasheet - Page 195

• Manufacturer Part Number: PIC18F6680-I/L
• Description: Microcontrollers (MCU) 64KB 3328 RAM 52 I/O
• Manufacturer: Microchip Technology

Specifications of PIC18F6680-I/L

• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3.25 KB
• Interface Type: I2C/SPI/AUSART/CAN
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 53
• Number Of Timers: 5
• Operating Supply Voltage: 4.2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12-ch x 10-bit
• Program Memory Type: Flash
• Program Memory Size: 64 KB
• Package / Case: PLCC-68
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.3.3
To enable the serial port, SSP Enable bit, SSPEN
(SSPCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPCON registers and then set the SSPEN bit. This
configures the SDI, SDO, SCK and SS pins as serial
port pins. For the pins to behave as the serial port func-
tion, some must have their data direction bits (in the
TRIS register) appropriately programmed as follows:
• SDI is automatically controlled by the SPI module
• SDO must have TRISC<5> bit cleared
• SCK (Master mode) must have TRISC<3> bit
• SCK (Slave mode) must have TRISC<3> bit set
• SS must have TRISF<7> bit set
Any serial port function that is not desired may be
overridden by programming the corresponding data
direction (TRIS) register to the opposite value.
FIGURE 17-2:
 2004 Microchip Technology Inc.
cleared
SPI Master SSPM3:SSPM0 = 00xxb
ENABLING SPI I/O
MSb
PROCESSOR 1
Serial Input Buffer
SPI MASTER/SLAVE CONNECTION
Shift Register
(SSPBUF)
(SSPSR)
LSb
SDO
SCK
SDI
PIC18F6585/8585/6680/8680
Serial Clock
17.3.4
Figure 17-2 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 pro-
grammed clock edge and latched on the opposite edge
of the clock. Both processors should be programmed to
the 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
SDO
SCK
SDI
SPI Slave SSPM3:SSPM0 = 010xb
TYPICAL CONNECTION
MSb
Serial Input Buffer
Shift Register
PROCESSOR 2
(SSPBUF)
(SSPSR)
LSb
DS30491C-page 193