Datasheet

1)(SPIBRR
LSPCLK
rateBaud
+
=
127to3SPIBRRwhen =
4
LSPCLK
rateBaud =
21,0,SPIBRRwhen =
TMS320F28030, TMS320F28031, TMS320F28032
TMS320F28033, TMS320F28034, TMS320F28035
www.ti.com SPRS584J –APRIL 2009–REVISED OCTOBER 2013
4.3 Serial Peripheral Interface (SPI) Module
The device includes the four-pin serial peripheral interface (SPI) module. Up to two SPI modules are
available. The SPI is a high-speed, synchronous serial I/O port that allows a serial bit stream of
programmed length (one to sixteen bits) to be shifted into and out of the device at a programmable bit-
transfer rate. Normally, the SPI is used for communications between the MCU and external peripherals or
another processor. Typical applications include external I/O or peripheral expansion through devices such
as shift registers, display drivers, and ADCs. Multidevice communications are supported by the
master/slave operation of the SPI.
The SPI module features include:
• Four external pins:
– SPISOMI: SPI slave-output/master-input pin
– SPISIMO: SPI slave-input/master-output pin
– SPISTE: SPI slave transmit-enable pin
– SPICLK: SPI serial-clock pin
NOTE: All four pins can be used as GPIO if the SPI module is not used.
• Two operational modes: master and slave
Baud rate: 125 different programmable rates.
• Data word length: one to sixteen data bits
• Four clocking schemes (controlled by clock polarity and clock phase bits) include:
– Falling edge without phase delay: SPICLK active-high. SPI transmits data on the falling edge of the
SPICLK signal and receives data on the rising edge of the SPICLK signal.
– Falling edge with phase delay: SPICLK active-high. SPI transmits data one half-cycle ahead of the
falling edge of the SPICLK signal and receives data on the falling edge of the SPICLK signal.
– Rising edge without phase delay: SPICLK inactive-low. SPI transmits data on the rising edge of the
SPICLK signal and receives data on the falling edge of the SPICLK signal.
– Rising edge with phase delay: SPICLK inactive-low. SPI transmits data one half-cycle ahead of the
falling edge of the SPICLK signal and receives data on the rising edge of the SPICLK signal.
• Simultaneous receive and transmit operation (transmit function can be disabled in software)
• Transmitter and receiver operations are accomplished through either interrupt-driven or polled
algorithms.
• Nine SPI module control registers: Located in control register frame beginning at address 7040h.
NOTE
All registers in this module are 16-bit registers that are connected to Peripheral Frame 2.
When a register is accessed, the register data is in the lower byte (7–0), and the upper byte
(15–8) is read as zeros. Writing to the upper byte has no effect.
Enhanced feature:
• 4-level transmit/receive FIFO
• Delayed transmit control
• Bi-directional 3 wire SPI mode support
• Audio data receive support via SPISTE inversion
Copyright © 2009–2013, Texas Instruments Incorporated Peripherals 65
Submit Documentation Feedback
Product Folder Links: TMS320F28030 TMS320F28031 TMS320F28032 TMS320F28033 TMS320F28034
TMS320F28035