PIC16F7X
9.0
9.1
SYNCHRONOUS SERIAL PORT
(SSP) MODULE
SSP Module Overview
9.2
SPI Mode
The Synchronous Serial Port (SSP) module is a serial
interface useful for communicating with other periph-
eral 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
2
C)
An overview of I
2
C operations and additional informa-
tion on the SSP module can be found in the PICmicro™
Mid-Range
MCU
Family
Reference Manual
(DS33023).
Refer to Application Note AN578, “Use of the SSP
Module in the I
2
C Multi-Master Environment”
(DS00578).
This section contains register definitions and opera-
tional characteristics of the SPI module. Additional
information on the SPI module can be found in the
PICmicro™ Mid-Range MCU Family Reference Man-
ual (DS33023A).
SPI mode allows 8 bits of data to be synchronously
transmitted and received simultaneously. To accom-
plish communication, typically three pins are used:
• Serial Data Out (SDO) RC5/SDO
• Serial Data In (SDI) RC4/SDI/SDA
• Serial Clock (SCK) RC3/SCK/SCL
Additionally, a fourth pin may be used when in a Slave
mode of operation:
• Slave Select (SS) RA5/SS/AN4
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 fol-
lowing 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)
• Clock Rate (Master mode only)
• Slave Select mode (Slave mode only)
2002 Microchip Technology Inc.
DS30325B-page 59
MICROCHIP [ MICROCHIP TECHNOLOGY ]
