PIC16F874-20/P Microchip Technology, PIC16F874-20/P Datasheet - Page 226

• Manufacturer Part Number: PIC16F874-20/P
• Description: IC MCU FLASH 4KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874-20/P

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Eeprom Size: 128 x 8
• Ram Size: 192 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
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: MSSP/PSP/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: 0 C
• On-chip Adc: 8-ch x 10-bit
• 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

PICmicro MID-RANGE MCU FAMILY
15.3
15.3.1
DS31015A-page 15-6
Operation
SPI Mode
The SPI mode allows 8-bits of data to be synchronously transmitted and received simulta-
neously. All four modes of SPI are supported, as well as Microwire™ (sample edge) when the
SPI is in the master mode.
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>) and SSPSTAT<7:6>. 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 (Idle state of SCK)
• Clock edge (output data on rising/falling edge of SCK)
• Data Input Sample Phase
• Clock Rate (Master mode only)
• Slave Select Mode (Slave mode only)
Figure 15-1
Figure 15-1:
shows the block diagram of the SSP module, when in SPI mode.
SSP Block Diagram (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