Altium教程PortSwitcher 1A软件设计1A

PortSwitcher 1软件设计第一部分 原理图1.1 PortSwitcherFPGA1C_Evalboard.SchDocEs tablis h a connection us ing Windows HyperTerminalA connnection file(PortSwitcherFPGA1C_Evalboard.ht) can be found in the main directory of this example - right clicking on a SchDoc of the project from within the Project Panels and s electing the Explore command will open this directory.Port s etting- 57600 Bits per s ec - 8 Data Bits - No Parity - 1 Stop Bit- No Hardware Flow ControlASCII s etting- Echo typed characters locally- Append line feeds to incoming line endsPortSwitcher Commands - h or ? print helpus ControllerUs DAA12Y171.2portswitcher1c.c// Simple port switching controller// Control is via an RS-232 port using the TKS51A embedded serial port// A very light weight comms suite and command interpreter is implemented. // Literal strings are used in-line - usually not an efficient practice.//#define NULL 0#define FALSE 0#define TRUE 1// Buffer lengths are short to prevent the need for external RAM// Only idata is used.#define TX_BUFFER_LENGTH 16#define RX_BUFFER_LENGTH 16#define RX_CMD_TERMINATOR 0x0D // <CR>#define RX_CMD_BACKSPACE 0x08 // <CR>#define NUMBER_OF_PORTS 4#define CLK_FREQ 3U*11059200UL // about 33.178 MHz#define BAUD_RATE 57600UL// Save ram space by keeping all strings in ROM if// possible#pragma romstring// Globals - resource limited processor and simple// demonstration program. Globals are being used.// version string__rom char sVersion[] = "PrtSw Ver 1.3 ";__rom char sDate[] = __DATE__" "; // Date with appended space __rom char sTime[] = __TIME__;// RS-232 receive buffers// These buffers are quite restricted in length and so// overflow will have to be managed (it has to be managed// regardless of length, but in this instance we will// no doubt have plenty of instances of overflow).// In the first instance overflow shall be managed by// discarding characters up until the next command// terminator (v. simple).// Two buffers are provided to allow for ping-ponging// between them as one is being dealt with at the the// higher level and one is receiving characters from// the receive ISR.char rxBuffer1[RX_BUFFER_LENGTH];char rxBuffer2[RX_BUFFER_LENGTH];unsigned char rxBuffer1Length = 0;unsigned char rxBuffer2Length = 0;__bit rxBuffer1Ready = FALSE;__bit rxBuffer2Ready = FALSE;// RS-232 transmit buffers// Very limited in length to conserve// RAM space. Note that ROM-based// messages can be longer.char txBuffer[TX_BUFFER_LENGTH];unsigned char txBufferLength = 0;// ISR variablesconst char *isrTXBuf;__rom char *isrTXBufROM;// Code space is more available than RAM// so I use a separate pointer to dump// ROM-based messages. Rather than copying// the ROM messages into a RAM buffer.unsigned char isrTXLength;unsigned char isrTXIndex;__bit isrTXFromRom; // TRUE if transmitting a ROM-based messagechar *isrRXBuf;unsigned char isrRXLength;__bit isrUsingRXBuffer1;// ROM-based messaged - see also Version variables at the top__rom const char txBufferPrompt[] = "cmd>";#define PROMPT_LENGTH sizeof(txBufferPrompt)/sizeof(char)-1__rom const char txBufferCR = 0x0d;// Shadow registers// Some of the I/O ports require shadow registers for correct operation // as not all the pins are the same direction and the port out and// in busses are not hardwired together.// This demonstrates a possible difference between an embedded 8051// and a traditional chip.unsigned char P1_ShadowReg;// Forward declarations of function prototypesvoid ClearBuffer(char *cmdBuffer);_Bool DoCommand(const char *cmdBuffer); // Simple command interpreter void PrintHelp(void); // Print simple helpvoid PrintPrompt(void); // Print a small promptvoid PrintVersion(void);_Bool Transmit(const char *msg, const unsigned char length);_Bool TransmitRomMsg(__rom char * msg, unsigned char length);_Bool TransmitCR(void);_Bool TransmitPrompt(void);void Init(void);void SetupSerialPort(void);_Bool Connect(unsigned char destPort, unsigned char srcPort);_Bool SetPortState(unsigned char port, _Bool enable);_Bool GetPortState(unsigned char port);_Bool QueryPort(unsigned char port);_Bool DumpPort(unsigned char port);signed char QueryConnection(unsigned char port);unsigned char ConvertPortToIndex(unsigned char port);void delay(void){int i;for(i=0; i<0x1fff; i++){}}void main(void){Init();SetupSerialPort();TransmitCR();PrintVersion();TransmitCR();TransmitPrompt();ClearBuffer(rxBuffer1);ClearBuffer(rxBuffer2);while(1){// Simple Task Manager// Loop forever and check status of// signals from low level software.// Trigger high level tasks as required.if(rxBuffer1Ready){DoCommand(rxBuffer1);ClearBuffer(rxBuffer1);rxBuffer1Ready = FALSE; // allow ISR to use this buffer if it wishes }if(rxBuffer2Ready){DoCommand(rxBuffer2);ClearBuffer(rxBuffer2);rxBuffer2Ready = FALSE; // allow ISR to use this buffer if it wishes }}}void ClearBuffer(char *cmdBuffer){for(int i=0; i < RX_BUFFER_LENGTH; i++){cmdBuffer[i] = 0x00;}}// DoCommand is the (simple) command interpreter.// Command decoding and execution.// Assumes fixed format commands - each command handler// does its own parameter checking (though there is very// limited error handling)._Bool DoCommand(const char *cmdBuffer){_Bool bRetVal = FALSE;unsigned char i;unsigned char ch1, ch2;if(cmdBuffer != NULL){TransmitCR();switch(cmdBuffer[0]){case'?':case'H':// Dump helpPrintHelp();bRetVal = TRUE;break;case'v':case'V':// Dump versionPrintVersion();bRetVal = TRUE;break;case'e':case'E':// port enable/disable command// we expect an integer (port)// followed by another integer (1 or 0)// Subtract '1' from port to get zero based port.// Subtract '0' from integer to get 0 for '0' and 1 for '1'.// No error checking for nowch1 = ConvertPortToIndex(cmdBuffer[2]);if( ch1 == 0xff){// Parameter errorTransmitRomMsg("Invalid port", 12);}else{if( SetPortState( ch1, (cmdBuffer[4])-'0'))TransmitRomMsg("OK", 2);}else{TransmitRomMsg("Fail", 4);}}bRetVal = TRUE;break;case'm':case'M':// port mapping command// we expect an integer// followed by another integer// No error checking for now// See if we have alpha or numeric port references// Also deal with upper and lower casech1 = ConvertPortToIndex(cmdBuffer[2]);ch2 = ConvertPortToIndex(cmdBuffer[4]);if( ch1 == 0xff){// Parameter errorTransmitRomMsg("Invalid destination port", 24); }if( ch2 == 0xff){if( ch1 == 0xff){// add in <CR> if we have already printed an error messageTransmitCR();}// Parameter errorTransmitRomMsg("Invalid source port", 19);}if((ch1 != 0xff) && (ch2 != 0xff)){if( Connect(ch1, ch2)){TransmitRomMsg("OK", 2);}else{TransmitRomMsg("Fail", 4);}}bRetVal = TRUE;break;case'q':case'Q':// Query port mapping and enable state// We expect an integer giving the port to querych1 = ConvertPortToIndex(cmdBuffer[2]);if( ch1 == 0xff){// Parameter errorTransmitRomMsg("Invalid port", 12);}else if( !DumpPort(ch1)){TransmitRomMsg("Fail", 4);}bRetVal = TRUE;break;case'd':case'D':// Query port mapping and enable state for all portsfor(i=0; i<NUMBER_OF_PORTS; i++){if( !DumpPort(i)){TransmitRomMsg("Fail", 4);}TransmitCR();}bRetVal = TRUE;break;default:TransmitRomMsg("Huh?", 4);break;}TransmitCR();TransmitPrompt();}return bRetVal;}unsigned char ConvertPortToIndex(unsigned char port) {unsigned char index = port;if( (port >= '1') && (port <= '4')){index -= '1';}else if( (port >= 'a') && (port <= 'd')){index -= 'a';}else if( (port >= 'A') && (port <= 'D')){index -= 'A';}else{index = 0xff; // signal error}return index;}void PrintVersion(void){// Dump the version number and date and time.// will have to wait around for the dump to occur // as our buffers are too small to take the// full dump in one go.//// This code is not all that robust. If there is a// problem transmitting one part of the// message the rest will still be attempted - this// is probably not what is required.// Also, the wait for the TX system is infinite.// This should be a timed wait with error// recovery.TransmitRomMsg(sVersion, sizeof(sVersion)/sizeof(char)-1);TransmitRomMsg(sDate, sizeof(sDate)/sizeof(char)-1);TransmitRomMsg(sTime, sizeof(sTime)/sizeof(char)-1);}void PrintHelp(void){// Dump the help//// This code is not all that robust. If there is a// problem transmitting one part of the// message the rest will still be attempted - this// is probably not what is required.// Also, the wait for the TX system is infinite.// This should be a timed wait with error// recovery.TransmitRomMsg("v - print version", 25); TransmitCR();TransmitRomMsg("? or h - print help", 22); TransmitCR();TransmitRomMsg("e prt 1|0 - enable/disable prt (1=enable)", 41); TransmitCR();TransmitRomMsg("m dst src - drive dst outputs from src inputs", 45); TransmitCR();TransmitRomMsg("q prt - query prt connection and state" , 42); TransmitCR();TransmitRomMsg("d - dump all port connections and states", 48); TransmitCR(); }_Bool TransmitCR(void){return TransmitRomMsg(&txBufferCR, 1);}_Bool TransmitPrompt(void){return TransmitRomMsg(txBufferPrompt, PROMPT_LENGTH);}_Bool Transmit(const char * msg, unsigned char length){// This is a blocking function - it will// wait indefinitely until the serial port// is free. Not ideal but simple for now._Bool bRetVal = TRUE;// The following access of the isrTXLength variable// is atomic (byte variable) so we do not need to// disable interrupts.while(isrTXLength != 0){// Wait until the port is free.// We could put a timeout in here and return FALSE if// the TX fails.}isrTXBuf = msg; // not sure this will work on a ROM string?isrTXLength = length;isrTXIndex = 1; // we will send the 0'th character belowisrTXFromRom = FALSE;SBUF = msg[0]; // start the transmissionreturn bRetVal;}_Bool TransmitRomMsg(__rom char * msg, unsigned char length){// This is a blocking function - it will// wait indefinitely until the serial port// is free. Not ideal but simple for now._Bool bRetVal = TRUE;// The following access of the isrTXLength variable// is atomic (byte variable) so we do not need to// disable interrupts.while(isrTXLength != 0){// Wait until the port is free.// We could put a timeout in here and return FALSE if// the TX fails.}isrTXBufROM = msg; // not sure this will work on a ROM string?isrTXLength = length;isrTXIndex = 1; // we will send the 0'th character belowisrTXFromRom = TRUE;SBUF = msg[0]; // start the transmissionreturn bRetVal;}void Init(void){// Initialise ports for loopback and disabledunsigned char i;for(i=0; i<NUMBER_OF_PORTS; i++){SetPortState(i, FALSE);Connect(i, i);}}void SetupSerialPort(void){isrTXBuf = NULL;isrTXLength = 0;isrRXBuf = rxBuffer1;isrRXLength = 0;isrUsingRXBuffer1 = TRUE;SM0 = 0;SM1 = 1; // Mode 1 - 8-bit UARTSM2 = 0; // Disable multiprocessor featureTB8 = 0; // 9th bit (not used)RB8 = 0; // This is the rx stop bit.TI = 0; // Clr TX intRI = 0; // Clr RX int//Need to set up timer 1 for baud rate CLK_FREQ_MHZTR1 = 0; // stop timer 1PCON_bit(7) = 1; // SMOD = 1 -> high speed baud rate// baud rate divisorTL1 = 0; // initialise to zeroTH1 = 256U - (2 * CLK_FREQ/(12U*32U*BAUD_RATE));TMOD_bit(7) = 0; // disable GATETMOD_bit(6) = 0; // operate as timerTMOD_bit(5) = 1;TMOD_bit(4) = 0; // 8-bit timer auto-reload modeIT0 = 0;IE0 = 0;IT1 = 0;IE1 = 0;TR0 = 0; // timer 0 stoppedTF0 = 0;TR1 = 1; // timer 1 runningTF1 = 0;ES = 1;IE_bit(7) = 1;REN = 1; // enable reception}// Connect - the destination port outputs are driven from the// the inputs of the source port.// __putbit and __getbit could be used in this function.// Returns TRUE if both ports are within range, FALSE// otherwise (and no mapping change is done in this case)._Bool Connect(unsigned char destPort, unsigned char srcPort){_Bool bRetVal;// Are ports within range?if(destPort >= NUMBER_OF_PORTS || srcPort >= NUMBER_OF_PORTS){bRetVal = FALSE;}else{// first set save the current state of the dest port_Bool bSave = GetPortState(destPort);P0 &= ~(0x03 << (2*destPort)); // Clear the existing mapping for this port// This little hack only works when// NUMBER_OF_PORTS == 4!// Generally a more elaborate mechanism would// be required that cleared all the bits of// the port that control this destination port.P0 |= (srcPort << (2*destPort));SetPortState(destPort, bSave); // Restore port statebRetVal = TRUE;}return bRetVal;}// SetPortState - returns FALSE (0) if port is out of range.// returns TRUE (1) if port is within range// This function will only work correctly when// NUMBER_OF_PORTS is 8 or less._Bool SetPortState(unsigned char port, _Bool enable){_Bool bRetVal;// Do some parameter checkingif(port >= NUMBER_OF_PORTS){bRetVal = FALSE;}else{if(enable){P1_ShadowReg |= (1 << port); // OR in the correct port}else{P1_ShadowReg &= ~(1 << port); // AND out the correct port}P1 = P1_ShadowReg;bRetVal = TRUE;}return bRetVal;}// GetPortState - return FALSE (0) if port enable bit is not set or // if port is out of range (TRUE otherwise)._Bool GetPortState(unsigned char port){if(port >= NUMBER_OF_PORTS){return FALSE; // Warning - unstructured error return. }return (P1_ShadowReg & (1 << port));}_Bool DumpPort(unsigned char port){_Bool bRetVal = FALSE;signed char tmp;if(port < NUMBER_OF_PORTS){tmp = port + 'A';Transmit((const char *)&tmp, 1);TransmitRomMsg(" <- ", 4);// Extract the mappingtmp = QueryConnection(port);if(tmp >= 0 && tmp < NUMBER_OF_PORTS){tmp += 'A';Transmit((const char *)&tmp, 1);}else{// If we received an error display a question markTransmitRomMsg("?", 1);}if(GetPortState(port)){TransmitRomMsg(" enabled", 8);}else{TransmitRomMsg(" disabled", 9);}bRetVal = TRUE;}return bRetVal;}signed char QueryConnection(unsigned char port){signed char retVal = -1;if(port < NUMBER_OF_PORTS){// Extract the mappingretVal = P0;retVal >>= (2*port);retVal &= 0x03; // Only works for NUMBER_OF_PORTS = 4! }return retVal;}__interrupt(0x23) void SerialISR( void )char tempChar; // temporary variable to reduce the// amount of array dereferencing.// Is there a TX interrupt?if(TI){TI = 0; // clear int source as soon as possible to// minimise chances of missing an interrupt// send the next character (if any) out to the portif(isrTXIndex < isrTXLength){// Another char to send - determine what sort of pointer we should// use. When we are sending a ROM-based message use a// __rom char *. This saves having to copy the message into RAM.// RAM is very limited in this application - only idata.if(isrTXFromRom){// We are sending a ROM message so use the ROM pointerSBUF = isrTXBufROM[isrTXIndex++];}else{SBUF = isrTXBuf[isrTXIndex++];}}else{// signal that we have finished transmittingisrTXLength = 0;}} // end of if(TI) - transmit character handling// Is there an RX interrupt?if(RI){RI = 0; // clear int source as soon as possible to// minimise chances of missing an RX interrupttempChar = SBUF;// save this character away - if there is spaceif(isrRXLength < RX_BUFFER_LENGTH-1){// OK save itisrRXBuf[isrRXLength++] = tempChar;}else{// Lets signal something// I know! We can put the count of received chars onto// Port 2. But we will do this outside the test so it// is a useful count at all times.}// Deal with back spaces - watch for underflow of the// buffer.if(tempChar == RX_CMD_BACKSPACE){if(isrRXLength > 1){isrRXLength -= 2; // take off two to account for the just-added// backspace character}else{isrRXLength = 0; // only really useful for a signed variable}// Could print a space and then do the backspace again// but I don't want to have to deal with potential recursion in// calling the TX routines, or to possibly stuff up some outgoing// transmission by forceably inserting a character into the transmit// buffer.}// Debug ouput - Upper four bits of port 2 contain lower four bits of// tempChar and lower four bits of port 2 contains lower four bits of// isrRXLengthP2 = ((tempChar << 4) & 0xf0)|(0x0f & isrRXLength);//P2 = isrRXLength; // signal the number of received characters onto port 2// If the character was a command terminator then we need to// pass it up to the high level.if(tempChar == RX_CMD_TERMINATOR){// new command bufferif(isrUsingRXBuffer1){rxBuffer1Length = isrRXLength;// set up for further reception in the other RX bufferisrRXBuf = rxBuffer2;isrUsingRXBuffer1 = FALSE;rxBuffer1Ready = TRUE; // signal high level code }else{rxBuffer2Length = isrRXLength;isrRXBuf = rxBuffer1;isrUsingRXBuffer1 = TRUE;rxBuffer2Ready = TRUE;}isrRXLength = 0;} // end of if(tempChar == RX_CMD_TERMINATOR )} // end of if(RI) - receive character handling}。