dspic33fj128mc706at-i-pt Microchip Technology Inc., dspic33fj128mc706at-i-pt Datasheet - Page 197

• Manufacturer Part Number: dspic33fj128mc706at-i-pt
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

18.0
The Serial Peripheral Interface (SPI) module is a
synchronous serial interface useful for communicating
with other peripheral or microcontroller devices. These
peripheral devices may be serial EEPROMs, shift
registers, display drivers, ADC, etc. The SPI module is
compatible with SPI and SIOP from Motorola
FIGURE 18-1:
© 2009 Microchip Technology Inc.
Note:
SDOx
SCKx
SDIx
SSx
SERIAL PERIPHERAL
INTERFACE (SPI)
This data sheet summarizes the features of
the dsPIC33FJXXXMCX06A/X08A/X10A
family of devices. However, it is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to Section 18. “Serial
Peripheral Interface (SPI)” (DS70206) in
the “dsPIC33F Family Reference Manual”,
which is available from the Microchip web
site (www.microchip.com).
Read SPIxBUF
Control
Sync
Transfer
SPI MODULE BLOCK DIAGRAM
dsPIC33FJXXXMCX06A/X08A/X10A
SPIxRXB
bit 0
SPIxBUF
SPIxSR
Control
Clock
Shift Control
SPIxTXB
®
.
Transfer
Write SPIxBUF
Preliminary
Select
Edge
Each SPI module consists of a 16-bit shift register,
SPIxSR (where x = 1 or 2), used for shifting data in and
out, and a buffer register, SPIxBUF. A control register,
SPIxCON, configures the module. Additionally, a status
register, SPIxSTAT, indicates various status conditions.
The serial interface consists of 4 pins: SDIx (Serial Data
Input), SDOx (Serial Data Output), SCKx (Shift Clock
Input or Output) and SSx (Active-Low Slave Select).
In Master mode operation, SCK is a clock output, but in
Slave mode, it is a clock input.
16
Note:
Secondary
1:1 to 1:8
Prescaler
Internal Data Bus
In this section, the SPI modules are
referred to together as SPIx, or separately
as SPI1 and SPI2. Special Function Reg-
isters will follow a similar notation. For
example, SPIxCON refers to the control
register for the SPI1 or SPI2 module.
1:1/4/16/64
Prescaler
Primary
F
SPIxCON1<1:0>
SPIxCON1<4:2>
Enable
Master Clock
DS70594A-page 195
CY