PIC16F721-I/SO Microchip Technology, PIC16F721-I/SO Datasheet - Page 139

• Manufacturer Part Number: PIC16F721-I/SO
• Description: MCU PIC 4K FLASH 20-SOIC
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16F721-I/SO

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Core Processor: PIC
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Number Of I /o: 17
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 12x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SOIC (0.300", 7.50mm Width)
• Controller Family/series: PIC16F
• No. Of I/o's: 18
• Ram Memory Size: 256Byte
• Cpu Speed: 16MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.0
The Synchronous Serial Port (SSP) module is a serial
interface useful for communicating with other peripher-
als or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers, dis-
play drivers, A/D converters, etc. The SSP module can
operate in one of two modes:
• Serial Peripheral Interface (SPI)
• Inter-Integrated Circuit (I
17.1
The SPI mode allows 8 bits of data to be synchronously
transmitted and received, simultaneously. The SSP
module can be operated in one of two SPI modes:
• Master mode
• Slave mode
SPI is a full-duplex protocol, with all communication
being bidirectional and initiated by a master device. All
clocking is provided by the master device and all bits
are transmitted, MSb first. Care must be taken to
ensure that all devices on the SPI bus are setup to
allow all controllers to send and receive data at the
same time.
FIGURE 17-1:
 2010 Microchip Technology Inc.
SSP MODULE OVERVIEW
SPI Mode
SPI Master SSPM<3:0> = 00xx
MSb
Serial Input Buffer
Processor 1
Shift Register
TYPICAL SPI MASTER/SLAVE CONNECTION
(SSPBUF)
(SSPSR)
2
C™)
LSb
General I/O
SCK
SDO
SDI
Serial Clock
Slave Select
(optional)
A typical SPI connection between microcontroller
devices is shown in
than one slave device is accomplished via multiple
hardware slave select lines. External hardware and
additional I/O pins must be used to support multiple
slave select addressing. This prevents extra overhead
in software for communication.
For SPI 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)
SDO
SCK
SDI
SS
PIC16F/LF720/721
SPI Slave SSPM<3:0> = 010x
MSb
Serial Input Buffer
Shift Register
(SSPBUF)
(SSPSR)
Figure
Processor 2
17-1. Addressing of more
LSb
DS41430A-page 139