Microchip Technology MA330031-2 Data Sheet
2011-2013 Microchip Technology Inc.
DS70000657H-page 265
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X AND PIC24EPXXXGP/MC20X
18.0
SERIAL PERIPHERAL
INTERFACE (SPI)
INTERFACE (SPI)
The SPI module is a synchronous serial interface,
useful for communicating with other peripheral or
microcontroller devices. These peripheral devices can
be serial EEPROMs, shift registers, display drivers,
ADC Converters, etc. The SPI module is compatible
with Motorola
useful for communicating with other peripheral or
microcontroller devices. These peripheral devices can
be serial EEPROMs, shift registers, display drivers,
ADC Converters, etc. The SPI module is compatible
with Motorola
®
SPI and SIOP interfaces.
The dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/
50X and PIC24EPXXXGP/MC20X device family offers
two SPI modules on a single device. These modules,
which are designated as SPI1 and SPI2, are function-
ally identical. Each SPI module includes an eight-word
FIFO buffer and allows DMA bus connections. When
using the SPI module with DMA, FIFO operation can be
disabled.
50X and PIC24EPXXXGP/MC20X device family offers
two SPI modules on a single device. These modules,
which are designated as SPI1 and SPI2, are function-
ally identical. Each SPI module includes an eight-word
FIFO buffer and allows DMA bus connections. When
using the SPI module with DMA, FIFO operation can be
disabled.
The SPI1 module uses dedicated pins which allow for a
higher speed when using SPI1. The SPI2 module takes
advantage of the Peripheral Pin Select (PPS) feature to
allow for greater flexibility in pin configuration of the SPI2
module, but results in a lower maximum speed for SPI2.
See
higher speed when using SPI1. The SPI2 module takes
advantage of the Peripheral Pin Select (PPS) feature to
allow for greater flexibility in pin configuration of the SPI2
module, but results in a lower maximum speed for SPI2.
See
for
more information.
The SPIx serial interface consists of four pins, as
follows:
• SDIx: Serial Data Input
• SDOx: Serial Data Output
• SCKx: Shift Clock Input or Output
• SSx/FSYNCx: Active-Low Slave Select or Frame
The SPIx serial interface consists of four pins, as
follows:
• SDIx: Serial Data Input
• SDOx: Serial Data Output
• SCKx: Shift Clock Input or Output
• SSx/FSYNCx: Active-Low Slave Select or Frame
Synchronization I/O Pulse
The SPIx module can be configured to operate with
two, three or four pins. In 3-pin mode, SSx is not used.
In 2-pin mode, neither SDOx nor SSx is used.
two, three or four pins. In 3-pin mode, SSx is not used.
In 2-pin mode, neither SDOx nor SSx is used.
illustrates the block diagram of the SPIx
module in Standard and Enhanced modes.
Note 1:
This data sheet summarizes the
features of the dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X and
PIC24EPXXXGP/MC20X families of
devices. It is not intended to be a
comprehensive reference source. To com-
plement the information in this data sheet,
refer to “Serial Peripheral Interface
(SPI)”
features of the dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X and
PIC24EPXXXGP/MC20X families of
devices. It is not intended to be a
comprehensive reference source. To com-
plement the information in this data sheet,
refer to “Serial Peripheral Interface
(SPI)”
(DS70569) in the “dsPIC33/PIC24
Family Reference Manual
”, which is avail-
www.microchip.com
).
2:
Some registers and associated bits
described in this section may not be
available on all devices. Refer to
described in this section may not be
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
Note:
In this section, the SPI modules are
referred to together as SPIx, or separately
as SPI1 and SPI2. Special Function
Registers follow a similar notation. For
example, SPIxCON refers to the control
register for the SPI1 and SPI2 modules.
referred to together as SPIx, or separately
as SPI1 and SPI2. Special Function
Registers follow a similar notation. For
example, SPIxCON refers to the control
register for the SPI1 and SPI2 modules.