PIC18F2550-I/SP Microchip Technology, PIC18F2550-I/SP Datasheet - Page 22

• Manufacturer Part Number: PIC18F2550-I/SP
• Description: IC PIC MCU FLASH 16KX16 28DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2550-I/SP

• Program Memory Type: FLASH
• Program Memory Size: 32KB (16K x 16)
• Package / Case: 28-DIP (0.300", 7.62mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 24
• Eeprom Size: 256 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1536 B
• Interface Type: SPI, I2C, EAUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 4
• 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, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163025, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 10 Channel
• Package: 28SPDIP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: I3-DB18F4550 - BOARD DAUGHTER ICEPIC3DM163025 - PIC DEM FULL SPEED USB DEMO BRDDVA18XP280 - DEVICE ADAPTER 18F2220 PDIP 28LD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2455/2550/4455/4550
10. Module: MSSP (SPI Master)
EXAMPLE 10:
DS80478A-page 22
TransmitSPI:
BCF
MOVF
MOVWF
BCF
CLRF
MOVF
MOVWF
BSF
WaitComplete:
BTFSS
BRA
In Section 19.3.5, “Master Mode,” the following
content is added:
When used in Timer2 Output/2 mode, the SPI bit
rate can be configured using the PR2 Period
register and the Timer2 prescaler.
To operate in this mode, firmware must first ini-
tialize and enable the Timer2 module before it
can be used with the MSSP. Once enabled, the
Timer2 module is free-running and mostly
independent of the MSSP module.
PIR1, SSPIF
SSPBUF, W
RXDATA
T2CON, TMR2ON
TMR2
TXDATA, W
SSPBUF
T2CON, TMR2ON
PIR1, SSPIF
WaitComplete
LOADING SSPBUF WITH THE TIMER2/2 CLOCK MODE
;Make sure interrupt flag is clear (may have been set from previous
;transmission)
;Perform read, even if the data in SSPBUF is not important
;Save previously received byte in user RAM, if the data is meaningful
;Turn off timer when loading SSPBUF
;Set timer to a known state
;WREG = Contents of TXDATA (user data to send)
;Load data to send into transmit buffer
;Start timer to begin transmission
;Loop until data has finished transmitting
;Interrupt flag set when transmit is complete
Writing to the SSPBUF register will not clear the
current TMR2 value in hardware. This can result
in an unpredictable SPI transmit MSb bit width,
depending on how close the TMR2 register was
to the PR2 match condition at the moment that
the firmware wrote to SSPBUF.
To avoid the unpredictable MSb bit width, initial-
ize the TMR2 register to a known value when
writing to SSPBUF. An example procedure,
which provides predictable bit widths (only
needed in the Timer2/2 mode), is given in
Example 10.
© 2009 Microchip Technology Inc.