Spi f28x
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The document provides an overview of the Serial Peripheral Interface (SPI) for the TMS320F2812 digital signal controller, detailing its data flow, architecture, and operational registers. It explains the communication setup between master and slave devices, data length programmability, and configuration registers. Additionally, it includes examples of using the SPI interface with devices like the DAC TLV 5617 and EEPROM M95080, along with their respective operational commands and timing diagrams.
Spi f28x
- 1. Chapter 7 : Serial Peripheral Interface C28x Digital Signal Controller TMS320F2812 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 2. SPI Data Flow • Simultaneous transmits and receive • SPI Master provides the clock signal SPI Device #1 - Master SPI Device #2 - Slave shift shift SPI Shift Register SPI Shift Register SPI Shift Register SPI Shift Register clock Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 3. SPI Block Diagram C28x - SPI Master Mode Shown SPISIMO RX FIFO_0 RX FIFO_15 SPIRXBUF.15-0 MSB LSB SPIDAT.15-0 SPISOMI SPITXBUF.15-0 TX FIFO_0 TX FIFO_15 baud clock clock LSPCLK rate polarity phase SPICLK Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 4. SPI Data Character Justification • Programmable data length of 1 to 16 bits SPIDAT - Processor #1 • Transmitted data of less than 16 bits must be left justified 11001001XXXXXXXX 11001001XXXXXXXX – MSB transmitted first • Received data of less than 16 bits are right justified • User software must mask-off SPIDAT - Processor #2 unused MSB’s XXXXXXXX11001001 XXXXXXXX11001001 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 5. SPI-A Registers Address Register Name 0x007040 SPICCR SPI-A configuration control register 0x007041 SPICTL SPI-A operation control register 0x007042 SPISTS SPI-A status register 0x007044 SPIBRR SPI-A baud rate register 0x007046 SPIEMU SPI-A emulation buffer register 0x007047 SPIRXBUF SPI-A serial receive buffer register 0x007048 SPITXBUF SPI-A serial transmit buffer register 0x007049 SPIDAT SPI-A serial data register 0x00704A SPIFFTX SPI-A FIFO transmit register 0x00704B SPIFFRX SPI-A FIFO receive register 0x00704C SPIFFCT SPI-A FIFO control register 0x00704F SPIPRI SPI-A priority control register Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 6. SPI-A Configuration Control Register SPICCR @ 0x007040 15-8 7 6 5-4 3 2 1 0 reserved reserved SPI CHAR.3-0 character length = number + 1 e.g. 0000b ⇒ length = 1 1111b ⇒ length = 16 CLOCK POLARITY 0 = rising edge data transfer 1 = falling edge data transfer SPI SW RESET 0 = SPI flags reset 1 = normal operation Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 7. SPI-A Operation Control Register SPICTL @ 0x007041 OVERRUN INT ENABLE MASTER/SLAVE 0 = disabled 0 = slave SPI INT ENABLE 1 = enabled 1 = master 0 = disabled 1 = enabled 15-5 4 3 2 1 0 reserved CLOCK PHASE TALK 0 = no CLK delay 0 = transmission disabled, 1 = CLK delayed 1/2 cycle output pin hi-Z’d 1 = transmission enabled Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 8. SPI-A Baud Rate Register SPIBRR @ 0x007044 Need to set this only when in master mode! 15-7 6-0 reserved SPI BIT RATE LSPCLK , SPIBRR = 3 to 127 (SPIBRR + 1) SPICLK signal = LSPCLK , SPIBRR = 0, 1, or 2 4 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 9. SPI-A Status Register 15-8 SPISTS @ 0x0070424-0 7 6 5 reserved reserved TX BUF FULL (read only) • Set to 1 when char written to SPITXBUF • Cleared when char in SPIDAT SPI INT FLAG (read only) • Set to 1 when transfer completed • Interrupt requested if SPI INT ENA bit set (SPICTL.0) • Cleared by reading SPIBRXUF RECEIVER OVERRUN (read/clear only) • Set to 1 if next reception completes before SPIRXBUF read • Interrupt requested if OVERRUN INT ENA bit set (SPICTL.4) • Cleared by writing a 1 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 10. SPI-A FIFO Transmit Register SPIFFTX @ 0x00704A FIFO Status (read-only) TX SPI FIFO 00000 TX FIFO empty TX FIFO Reset 00001 TX FIFO has 1 word Enhancements 0 = reset (pointer to 0) 00010 0 = disable TX FIFO has 2 words 1 = enable operation 00011 . TX FIFO.has 3 words. 1 = enable . . . . . . 10000 TX FIFO has 16 words 15 14 13 12 11 10 9 8 TXFIFO reserved SPIFFEN TXFFST4 TXFFST3 TXFFST2 TXFFST1 TXFFST0 RESET 7 6 5 4 3 2 1 0 TXFFINT TXFFINT TXFFIEN TXFFIL4 TXFFIL3 TXFFIL2 TXFFIL1 TXFFIL0 CLR TX FIFO TX FIFO TX FIFO TX FIFO Interrupt Level Interrupt Interrupt Interrupt Flag (read-only) Flag Clear (on match) Interrupt when TXFFST4-0 0 = not occurred 0 = no effect Enable and TXFFIL4-0 match 1 = occurred 1 = clear 0 = disable 1 = enable Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 11. SPI-A FIFO Receive Register SPIFFRX @ 0x00704B RX FIFO Status (read-only) RX FIFO RX FIFO 00000 RX FIFO empty Overflow Overflow RX FIFO Reset00001 RX FIFO has 1 word Flag (read-only) Flag Clear 0 = reset (pointer to00010 0) RX FIFO has 2 words 0 = no overflow 0 = no effect 1 = enable operation 00011 . RX FIFO.has 3 words. 1 = overflow 1 = clear . . . . . . 10000 RX FIFO has 16 words 15 14 13 12 11 10 9 8 RXFF- RXFF- RXFIFO RXFFST4 RXFFST3 RXFFST2 RXFFST1 RXFFST0 OVF OVF CLR RESET 7 6 5 4 3 2 1 0 RXFFINT RXFFINT RXFFIEN RXFFIL4 RXFFIL3 RXFFIL2 RXFFIL1 RXFFIL0 CLR RX FIFO RX FIFO RX FIFO RX FIFO Interrupt Level Interrupt Interrupt Interrupt Flag (read-only) Flag Clear (on match) Interrupt when RXFFST4-0 0 = not occurred 0 = no effect Enable and RXFFIL4-0 match 1 = occurred 1 = clear 0 = disable 1 = enable Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 12. SPI Summary • Provides synchronous serial communications – Two wire transmit or receive (half duplex) – Three wire transmit and receive (full duplex) • Software configurable as master or slave – C28x provides clock signal in master mode • Data length programmable from 1-16 bits • 125 different programmable baud rates Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 13. SPI Example 1: DAC TLV 5617 • Texas Instruments Digital to Analogue Converter (DAC) TLV 5617A – 10 MBPS SPI Data Communication – Dual Channel Analogue Output ( Out A + B) – 10 Bit resolution – /CS is connected to C28x GPIO – D0 at the Zwickau Adapter Board – REF – Voltage defines Analogue Range / 2 – SOIC-8 – Operating Voltage : 0 to 3.3V Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 14. SPI Example : DAC TLV 5617 • Timing Diagram: © Texas Instruments SLAS234F – JULY 1999 – REVISED JULY 2002 ; page 6 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 15. SPI Example : DAC TLV 5617 • Serial Data Format: SPD PWR Speed Control Power Control 0 = slow mode 0 = normal operation 1 = fast mode 1 = power down 15 14 13 12 11 10 9 8 R1 SPD PWR R0 DATA9 DATA8 DATA7 DATA6 7 6 5 4 3 2 1 0 DATA5 DATA4 DATA3 DATA2 DATA1 DATA0 0 0 R1 , R0 Register Select 00: Write to DACB and Buffer 01: Write to Buffer 10: Write to DACA and update DACB with Buffer 11: reserved Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 16. Lab 7: DAC TLV 5617 • Objective: – Generate a rising saw-tooth (0V…3.3V) at channel OUTA and a falling saw- tooth (3.3V…0V) at channel OUTB – GPIO – D0 is DAC’s chip select (/CS) at the Zwickau Adapter Board – To measure the DAC outputs: • Use JP7 for OUTA • Use JP8 for OUTB ( Zwickau Adapter Board) – REF = 3.3V – Feedback the voltages into the C28x ADC: • JP7 closed: OUTA ADCINA1 • JP8 closed: OUTB ADCINB1 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 17. SPI Example 2: EEPROM M95080 • ST Microelectronics EEPROM M95080 – 10 MBPS SPI Data Communication – Capacity: 1024 x 8 Bit – /CS is connected to C28x GPIO – D5 (Zwickau Adapter Board) – 6 Instructions: • Write Enable, Write Disable • Read Status Register, Write Status Register • Read Data, Write Data – SOIC-8 – Single Power Supply : 3.3V Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 18. SPI Example : EEPROM M95080 • Timing Diagram: © ST Microelectronics Datasheet M95080 – November 2002, page 4 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 19. SPI Example : EEPROM M95080 M95080 Status Register: 7 6 5 4 3 2 1 0 SRWD 0 0 0 BP1 BP0 WEL WIP Block protect select Write in progress 00 = no protection 0 = no write cycle 01 = 0x300 – 0x3FF protected 1 = write in progress 10 = 0x200 – 0x3FF protected 11 = 0x000 – 0x3FF protected Write Enable Latch Status Register Write Protect 0 = write disabled 1 = no write access to SR 1 = write enabled 0 = normal operation Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 20. SPI Example : EEPROM M95080 Instruction Description Code WREN Write Enable 0000 0110 WRDI Write Disable 0000 0100 E Read Status 0000 0101 Register WDSR Write Status 0000 0001 Register READ Read Data 0000 0011 WRITE Write Data 0000 0010 M95080 Instruction Sets Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 21. SPI Example : EEPROM M95080 • Timing Diagram WREN: © ST Microelectronics ; Datasheet (8028.pdf) – November 2002; Page 8 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 22. SPI Example : EEPROM M95080 • Timing Diagram RDSR: © ST Microelectronics ; Datasheet (8028.pdf) – November 2002; Page 10 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 23. SPI Example : EEPROM M95080 • Timing Diagram READ: © ST Microelectronics ; Datasheet (8028.pdf) – November 2002; Page 13 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 24. SPI Example : EEPROM M95080 • Timing Diagram WRITE: © ST Microelectronics ; Datasheet (8028.pdf) – November 2002; Page 14 Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt
- 25. Lab 7B: EEPROM M95080 • Objective: – Based on hardware of Zwickau Adapter Board – Store the value of 8 input switches (GPIO – B15…B8) into EEPROM – Address 0x40 when command input button GPIO-D1 is pressed (low active). – Read EEPROM-Address 0x40 and show its content on 8 LED’s ( GPIO-B7… B0) when command input button GPIO-D6 is pressed (low active). – GPIO – D5 is EEPROM’s chip select (/CS) at the Zwickau Adapter Board Technology beyond the Dreams™ Copyright © 2006 Pantech Solutions Pvt