PIC18F86K90-I/PT Microchip Technology, PIC18F86K90-I/PT Datasheet - Page 305

• Manufacturer Part Number: PIC18F86K90-I/PT
• Description: 64kB Flash, 4kB RAM, 1kB EE, 16MIPS, NanoWatt XLP, LCD, 5V 80 TQFP 12x12x1mm TRA
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F86K90-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

21.3.4
To enable the serial port, MSSP Enable bit, SSPEN
(SSPxCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPxCON registers and then set the SSPEN bit. This
configures the SDIx, SDOx, SCKx and SSx pins as
serial port pins. For the pins to behave as the serial port
function, some must have their data direction bits (in
the TRIS register) appropriately programmed as
follows:
• SDIx is automatically controlled by the
• SDOx must have the TRISC<5> or TRISD<4> bit
• SCKx (Master mode) must have the TRISC<3> or
• SCKx (Slave mode) must have the TRISC<3> or
• SSx must have the TRISF<7> or TRISD<7> bit set
FIGURE 21-2:
 2010 Microchip Technology Inc.
SPI module
cleared
TRISD<6>bit cleared
TRISD<6> bit set
ENABLING SPI I/O
SPI Master SSPM<3:0> = 00xxb
MSb
PROCESSOR 1
Serial Input Buffer
SPI MASTER/SLAVE CONNECTION
Shift Register
(SSPxBUF)
(SSPxSR)
LSb
SDOx
SCKx
SDIx
Preliminary
Serial Clock
PIC18F87K90 FAMILY
Any serial port function that is not desired may be
overridden by programming the corresponding Data
Direction (TRIS) register to the opposite value.
21.3.5
Figure 21-2 shows a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCKx 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
SDOx
SCKx
SDIx
TYPICAL CONNECTION
SPI Slave SSPM<3:0> = 010xb
MSb
Serial Input Buffer
Shift Register
(SSPxBUF)
PROCESSOR 2
(SSPxSR)
LSb
DS39957B-page 305