391 lines
12 KiB
C
391 lines
12 KiB
C
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// TI File $Revision: /main/11 $
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// Checkin $Date: April 21, 2008 15:43:14 $
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//###########################################################################
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//
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// FILE: Example_2833xSci_Autobaud_.c
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//
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// TITLE: DSP2833x SCI Autobaud detect example
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//
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// ASSUMPTIONS:
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//
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// This program requires the DSP2833x header files.
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//
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// Test requires the following hardware connections:
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//
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// GPIO29/SCITXDA <-> GPIO19/SCIRXDB
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// GPIO28/SCIRXDA <-> GPIO18/SCITXDB
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//
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//
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// As supplied, this project is configured for "boot to SARAM"
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// operation. The 2833x Boot Mode table is shown below.
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// For information on configuring the boot mode of an eZdsp,
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// please refer to the documentation included with the eZdsp,
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//
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// $Boot_Table:
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//
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// GPIO87 GPIO86 GPIO85 GPIO84
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// XA15 XA14 XA13 XA12
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// PU PU PU PU
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// ==========================================
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// 1 1 1 1 Jump to Flash
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// 1 1 1 0 SCI-A boot
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// 1 1 0 1 SPI-A boot
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// 1 1 0 0 I2C-A boot
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// 1 0 1 1 eCAN-A boot
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// 1 0 1 0 McBSP-A boot
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// 1 0 0 1 Jump to XINTF x16
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// 1 0 0 0 Jump to XINTF x32
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// 0 1 1 1 Jump to OTP
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// 0 1 1 0 Parallel GPIO I/O boot
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// 0 1 0 1 Parallel XINTF boot
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// 0 1 0 0 Jump to SARAM <- "boot to SARAM"
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// 0 0 1 1 Branch to check boot mode
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// 0 0 1 0 Boot to flash, bypass ADC cal
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// 0 0 0 1 Boot to SARAM, bypass ADC cal
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// 0 0 0 0 Boot to SCI-A, bypass ADC cal
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// Boot_Table_End$
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//
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//
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// This test will perform autobaud lock at a variety of baud rates, including
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// very high baud rates.
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//
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// For this test to properly run, connect the SCI-A pins to the
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// SCI-B pins without going through a transciever.
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//
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// At higher baud rates, the slew rate of the incoming data bits can be
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// affected by transceiver and connector performance. This slew rate may
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// limit reliable autobaud detection at higher baud rates.
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//
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// SCIA: Slave, autobaud locks, receives characters and
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// echos them back to the host. Uses the RX interrupt
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// to receive characters.
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//
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// SCIB: Host, known baud rate, sends characters to the slave
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// and checks that they are echoed back.
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//
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// DESCRIPTION:
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//
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// Internal Loopback test for ever through SCIA using interrupts,
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// FIFOs are disabled.
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//
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// Watch Variables: BRRVal - current BRR value used for SCIB
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// ReceivedAChar - character received by SCIA
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// ReceivedBChar - character received by SCIB
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// SendChar - character being sent by SCIB
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// SciaRegs.SCILBAUD - SCIA baud registers - set
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// SciaRegs.SCIHBAUD by autobaud lock
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//
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//
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//###########################################################################
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// $TI Release: DSP2833x/DSP2823x Header Files V1.20 $
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// $Release Date: August 1, 2008 $
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//###########################################################################
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#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
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#define BAUDSTEP 100 // Amount BRR will be incremented between each
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// autobaud lock
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// Prototype statements for functions found within this file.
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void scia_init(void);
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void scib_init(void);
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void scia_xmit(int a);
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void scib_xmit(int a);
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void scia_AutobaudLock(void);
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void error();
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interrupt void rxaint_isr(void);
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// Global counts used in this example
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Uint16 LoopCount;
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//Uint16 xmitCount;
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Uint16 ReceivedCount;
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Uint16 ErrorCount;
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Uint16 SendChar;
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Uint16 ReceivedAChar; // scia received character
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Uint16 ReceivedBChar; // scib received character
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Uint16 BRRVal;
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Uint16 Buff[10] = {0x55, 0xAA, 0xF0, 0x0F, 0x00, 0xFF, 0xF5, 0x5F, 0xA5, 0x5A};
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void main(void)
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{
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Uint16 i;
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// Step 1. Initialize System Control:
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// PLL, WatchDog, enable Peripheral Clocks
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// This example function is found in the DSP2833x_SysCtrl.c file.
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InitSysCtrl();
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// Step 2. Initalize GPIO:
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// This example function is found in the DSP2833x_Gpio.c file and
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// illustrates how to set the GPIO to it's default state.
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// InitGpio(); // Skipped for this example
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InitSciGpio();
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// Initialize PIE control registers to their default state.
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// The default state is all PIE interrupts disabled and flags
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// are cleared.
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// This function is found in the DSP2833x_PieCtrl.c file.
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InitPieCtrl();
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// Disable CPU interrupts and clear all CPU interrupt flags:
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IER = 0x0000;
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IFR = 0x0000;
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// Initialize the PIE vector table with pointers to the shell Interrupt
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// Service Routines (ISR).
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// This will populate the entire table, even if the interrupt
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// is not used in this example. This is useful for debug purposes.
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// The shell ISR routines are found in DSP2833x_DefaultIsr.c.
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// This function is found in DSP2833x_PieVect.c.
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InitPieVectTable();
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// Interrupts that are used in this example are re-mapped to
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// ISR functions found within this file.
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EALLOW; // This is needed to write to EALLOW protected registers
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PieVectTable.SCIRXINTA = &rxaint_isr;
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EDIS; // This is needed to disable write to EALLOW protected register
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// Step 4. Initialize all the Device Peripherals:
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// This function is found in DSP2833x_InitPeripherals.c
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// InitPeripherals(); // Not required for this example
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scia_init(); // Initalize SCIA
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scib_init(); // Initalize SCIB
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// Step 5. User specific code, enable interrupts:
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LoopCount = 0;
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ErrorCount = 0;
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// Enable interrupts
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PieCtrlRegs.PIEIER9.all = 0x0001; // Enable all SCIA RXINT interrupt
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IER |= 0x0100; // enable PIEIER9, and INT9
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EINT;
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// Start with BRR = 1, work through each baud rate setting
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// incrementing BRR by BAUDSTEP
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for (BRRVal = 0x0000; BRRVal < (Uint32)0xFFFF; BRRVal+=BAUDSTEP)
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{
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// SCIB has a known baud rate. SCIA will autobaud to match
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ScibRegs.SCIHBAUD = (BRRVal >> 8);
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ScibRegs.SCILBAUD = (BRRVal);
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// Initiate an autobaud lock with scia. Check
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// returned character against baud lock character 'A'
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scia_AutobaudLock();
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while(ScibRegs.SCIRXST.bit.RXRDY != 1) { }
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ReceivedBChar = 0;
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ReceivedBChar = ScibRegs.SCIRXBUF.bit.RXDT;
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if(ReceivedBChar != 'A')
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{
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error(0);
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}
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// Send/echoback characters
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// 55 AA F0 0F 00 FF F5 5F A5 5A
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for(i= 0; i<=9; i++)
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{
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SendChar = Buff[i];
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scib_xmit(SendChar); // Initiate interrupts and xmit data in isr
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// Wait to get the character back and check
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// against the sent character.
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while(ScibRegs.SCIRXST.bit.RXRDY != 1)
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{
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asm(" NOP");
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}
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ReceivedBChar = 0;
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ReceivedBChar = ScibRegs.SCIRXBUF.bit.RXDT;
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if(ReceivedBChar != SendChar) error(1);
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}
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} // Repeat for next BRR setting
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// Stop here, no more
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for(;;)
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{
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asm(" NOP");
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}
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}
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/* --------------------------------------------------- */
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/* ISR for PIE INT9.1 */
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/* Connected to RXAINT SCI-A */
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/* ----------------------------------------------------*/
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interrupt void rxaint_isr(void) // SCI-A
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{
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// Insert ISR Code here
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PieCtrlRegs.PIEACK.all = PIEACK_GROUP9;
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// If autobaud detected, we must clear CDC
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if(SciaRegs.SCIFFCT.bit.ABD == 1)
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{
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SciaRegs.SCIFFCT.bit.ABDCLR = 1;
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SciaRegs.SCIFFCT.bit.CDC = 0;
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// Check received character - should be 'A'
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ReceivedAChar = 0;
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ReceivedAChar = SciaRegs.SCIRXBUF.all;
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if(ReceivedAChar != 'A')
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{
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error(2);
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}
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else scia_xmit(ReceivedAChar);
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}
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// This was not autobaud detect
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else
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{
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// Check received character against sendchar
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ReceivedAChar = 0;
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ReceivedAChar = SciaRegs.SCIRXBUF.all;
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if(ReceivedAChar != SendChar)
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{
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error(3);
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}
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else scia_xmit(ReceivedAChar);
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}
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SciaRegs.SCIFFRX.bit.RXFFINTCLR = 1; // clear Receive interrupt flag
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ReceivedCount++;
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}
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void error()
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{
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ErrorCount++;
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asm(" ESTOP0"); // Uncomment to stop the test here
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for (;;);
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}
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// SCIA 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity
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void scia_init()
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{
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// Note: Clocks were turned on to the SCIA peripheral
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// in the InitSysCtrl() function
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// Reset FIFO's
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SciaRegs.SCIFFTX.all=0x8000;
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SciaRegs.SCICCR.all =0x0007; // 1 stop bit, No loopback
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// No parity,8 char bits,
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// async mode, idle-line protocol
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SciaRegs.SCICTL1.all =0x0003; // enable TX, RX, internal SCICLK,
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// Disable RX ERR, SLEEP, TXWAKE
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SciaRegs.SCICTL2.all =0x0003;
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SciaRegs.SCICTL2.bit.RXBKINTENA =1;
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SciaRegs.SCICTL1.all =0x0023; // Relinquish SCI from Reset
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}
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// SCIB 8-bit word, baud rate 0x000F, default, 1 STOP bit, no parity
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void scib_init()
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{
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// Reset FIFO's
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ScibRegs.SCIFFTX.all=0x8000;
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// 1 stop bit, No parity, 8-bit character
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// No loopback
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ScibRegs.SCICCR.all = 0x0007;
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// Enable TX, RX, Use internal SCICLK
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ScibRegs.SCICTL1.all = 0x0003;
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// Disable RxErr, Sleep, TX Wake,
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// Diable Rx Interrupt, Tx Interrupt
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ScibRegs.SCICTL2.all = 0x0000;
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// Relinquish SCI-A from reset
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ScibRegs.SCICTL1.all = 0x0023;
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return;
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}
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// Transmit a character from the SCI-A'
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void scia_xmit(int a)
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{
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SciaRegs.SCITXBUF=a;
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}
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// Transmit a character from the SCI-B'
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void scib_xmit(int a)
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{
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ScibRegs.SCITXBUF=a;
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}
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//------------------------------------------------
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// Perform autobaud lock with the host.
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// Note that if autobaud never occurs
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// the program will hang in this routine as there
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// is no timeout mechanism included.
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//------------------------------------------------
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void scia_AutobaudLock()
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{
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SciaRegs.SCICTL1.bit.SWRESET = 0;
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SciaRegs.SCICTL1.bit.SWRESET = 1;
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// Must prime baud register with >= 1
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SciaRegs.SCIHBAUD = 0;
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SciaRegs.SCILBAUD = 1;
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// Prepare for autobaud detection
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// Make sure the ABD bit is clear by writing a 1 to ABDCLR
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// Set the CDC bit to enable autobaud detection
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SciaRegs.SCIFFCT.bit.ABDCLR = 1;
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SciaRegs.SCIFFCT.bit.CDC = 1;
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// Wait until we correctly read an
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// 'A' or 'a' and lock
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//
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// As long as Autobaud calibration is enabled (CDC = 1),
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// SCI-B (host) will continue transmitting 'A'. This will
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// continue until interrupted by the SCI-A RX ISR, where
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// SCI-A RXBUF receives 'A', autobaud-locks (ABDCLR=1
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// CDC=0),and returns an 'A' back to the host. Then control
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// is returned to this loop and the loop is exited.
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//
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// NOTE: ABD will become set sometime between
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// scib_xmit and the DELAY_US loop, and
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// the SCI-A RX ISR will be triggered.
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// Upon returning and reaching the if-statement,
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// ABD will have been cleared again by the ISR.
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while(SciaRegs.SCIFFCT.bit.CDC== 1)
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{
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// Note the lower the baud rate the longer
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// this delay has to be to allow the other end
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// to echo back a character (about 4 characters long)
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// Make this really long since we are going through all
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// the baud rates.
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DELAY_US(280000L);
|
||
|
|
|
||
|
|
if(SciaRegs.SCIFFCT.bit.CDC == 1)
|
||
|
|
scib_xmit('A'); // host transmits 'A'
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//===========================================================================
|
||
|
|
// No more.
|
||
|
|
//===========================================================================
|
||
|
|
|