// TI File $Revision: /main/8 $ // Checkin $Date: June 25, 2008 15:19:07 $ //########################################################################### // // FILE: DSP2833x_ECan.c // // TITLE: DSP2833x Enhanced CAN Initialization & Support Functions. // //########################################################################### // $TI Release: DSP2833x/DSP2823x Header Files V1.20 $ // $Release Date: August 1, 2008 $ //########################################################################### #include "DSP2833x_Device.h" // DSP2833x Headerfile Include File #include "DSP2833x_Examples.h" // DSP2833x Examples Include File //--------------------------------------------------------------------------- // InitECan: //--------------------------------------------------------------------------- // This function initializes the eCAN module to a known state. // void InitECan(void) { InitECana(); #if DSP28_ECANB InitECanb(); #endif // if DSP28_ECANB } void InitECana(void) // Initialize eCAN-A module { /* Create a shadow register structure for the CAN control registers. This is needed, since only 32-bit access is allowed to these registers. 16-bit access to these registers could potentially corrupt the register contents or return false data. This is especially true while writing to/reading from a bit (or group of bits) among bits 16 - 31 */ struct ECAN_REGS ECanaShadow; EALLOW; // EALLOW enables access to protected bits /* Configure eCAN RX and TX pins for CAN operation using eCAN regs*/ ECanaShadow.CANTIOC.all = ECanaRegs.CANTIOC.all; ECanaShadow.CANTIOC.bit.TXFUNC = 1; ECanaRegs.CANTIOC.all = ECanaShadow.CANTIOC.all; ECanaShadow.CANRIOC.all = ECanaRegs.CANRIOC.all; ECanaShadow.CANRIOC.bit.RXFUNC = 1; ECanaRegs.CANRIOC.all = ECanaShadow.CANRIOC.all; /* Configure eCAN for HECC mode - (reqd to access mailboxes 16 thru 31) */ // HECC mode also enables time-stamping feature ECanaShadow.CANMC.all = ECanaRegs.CANMC.all; ECanaShadow.CANMC.bit.SCB = 1; ECanaRegs.CANMC.all = ECanaShadow.CANMC.all; /* Initialize all bits of 'Master Control Field' to zero */ // Some bits of MSGCTRL register come up in an unknown state. For proper operation, // all bits (including reserved bits) of MSGCTRL must be initialized to zero ECanaMboxes.MBOX0.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX1.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX2.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX3.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX4.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX5.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX6.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX7.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX8.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX9.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX10.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX11.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX12.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX13.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX14.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX15.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX16.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX17.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX18.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX19.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX20.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX21.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX22.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX23.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX24.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX25.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX26.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX27.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX28.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX29.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX30.MSGCTRL.all = 0x00000000; ECanaMboxes.MBOX31.MSGCTRL.all = 0x00000000; // TAn, RMPn, GIFn bits are all zero upon reset and are cleared again // as a matter of precaution. ECanaRegs.CANTA.all = 0xFFFFFFFF; /* Clear all TAn bits */ ECanaRegs.CANRMP.all = 0xFFFFFFFF; /* Clear all RMPn bits */ ECanaRegs.CANGIF0.all = 0xFFFFFFFF; /* Clear all interrupt flag bits */ ECanaRegs.CANGIF1.all = 0xFFFFFFFF; /* Configure bit timing parameters for eCANA*/ ECanaShadow.CANMC.all = ECanaRegs.CANMC.all; ECanaShadow.CANMC.bit.CCR = 1 ; // Set CCR = 1 ECanaRegs.CANMC.all = ECanaShadow.CANMC.all; ECanaShadow.CANES.all = ECanaRegs.CANES.all; do { ECanaShadow.CANES.all = ECanaRegs.CANES.all; } while(ECanaShadow.CANES.bit.CCE != 1 ); // Wait for CCE bit to be set.. ECanaShadow.CANBTC.all = 0; #if (CPU_FRQ_150MHZ) // CPU_FRQ_150MHz is defined in DSP2833x_Examples.h /* The following block for all 150 MHz SYSCLKOUT (75 MHz CAN clock) - default. Bit rate = 1 Mbps See Note at End of File */ ECanaShadow.CANBTC.bit.BRPREG = 4; ECanaShadow.CANBTC.bit.TSEG2REG = 2; ECanaShadow.CANBTC.bit.TSEG1REG = 10; #endif #if (CPU_FRQ_100MHZ) // CPU_FRQ_100MHz is defined in DSP2833x_Examples.h /* The following block is only for 100 MHz SYSCLKOUT (50 MHz CAN clock). Bit rate = 1 Mbps See Note at End of File */ ECanaShadow.CANBTC.bit.BRPREG = 4; ECanaShadow.CANBTC.bit.TSEG2REG = 1; ECanaShadow.CANBTC.bit.TSEG1REG = 6; #endif ECanaShadow.CANBTC.bit.SAM = 1; ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all; ECanaShadow.CANMC.all = ECanaRegs.CANMC.all; ECanaShadow.CANMC.bit.CCR = 0 ; // Set CCR = 0 ECanaRegs.CANMC.all = ECanaShadow.CANMC.all; ECanaShadow.CANES.all = ECanaRegs.CANES.all; do { ECanaShadow.CANES.all = ECanaRegs.CANES.all; } while(ECanaShadow.CANES.bit.CCE != 0 ); // Wait for CCE bit to be cleared.. /* Disable all Mailboxes */ ECanaRegs.CANME.all = 0; // Required before writing the MSGIDs EDIS; } #if (DSP28_ECANB) void InitECanb(void) // Initialize eCAN-B module { /* Create a shadow register structure for the CAN control registers. This is needed, since only 32-bit access is allowed to these registers. 16-bit access to these registers could potentially corrupt the register contents or return false data. This is especially true while writing to/reading from a bit (or group of bits) among bits 16 - 31 */ struct ECAN_REGS ECanbShadow; EALLOW; // EALLOW enables access to protected bits /* Configure eCAN RX and TX pins for CAN operation using eCAN regs*/ ECanbShadow.CANTIOC.all = ECanbRegs.CANTIOC.all; ECanbShadow.CANTIOC.bit.TXFUNC = 1; ECanbRegs.CANTIOC.all = ECanbShadow.CANTIOC.all; ECanbShadow.CANRIOC.all = ECanbRegs.CANRIOC.all; ECanbShadow.CANRIOC.bit.RXFUNC = 1; ECanbRegs.CANRIOC.all = ECanbShadow.CANRIOC.all; /* Configure eCAN for HECC mode - (reqd to access mailboxes 16 thru 31) */ ECanbShadow.CANMC.all = ECanbRegs.CANMC.all; ECanbShadow.CANMC.bit.SCB = 1; ECanbRegs.CANMC.all = ECanbShadow.CANMC.all; /* Initialize all bits of 'Master Control Field' to zero */ // Some bits of MSGCTRL register come up in an unknown state. For proper operation, // all bits (including reserved bits) of MSGCTRL must be initialized to zero ECanbMboxes.MBOX0.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX1.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX2.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX3.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX4.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX5.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX6.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX7.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX8.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX9.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX10.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX11.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX12.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX13.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX14.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX15.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX16.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX17.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX18.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX19.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX20.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX21.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX22.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX23.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX24.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX25.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX26.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX27.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX28.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX29.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX30.MSGCTRL.all = 0x00000000; ECanbMboxes.MBOX31.MSGCTRL.all = 0x00000000; // TAn, RMPn, GIFn bits are all zero upon reset and are cleared again // as a matter of precaution. ECanbRegs.CANTA.all = 0xFFFFFFFF; /* Clear all TAn bits */ ECanbRegs.CANRMP.all = 0xFFFFFFFF; /* Clear all RMPn bits */ ECanbRegs.CANGIF0.all = 0xFFFFFFFF; /* Clear all interrupt flag bits */ ECanbRegs.CANGIF1.all = 0xFFFFFFFF; /* Configure bit timing parameters for eCANB*/ ECanbShadow.CANMC.all = ECanbRegs.CANMC.all; ECanbShadow.CANMC.bit.CCR = 1 ; // Set CCR = 1 ECanbRegs.CANMC.all = ECanbShadow.CANMC.all; ECanbShadow.CANES.all = ECanbRegs.CANES.all; do { ECanbShadow.CANES.all = ECanbRegs.CANES.all; } while(ECanbShadow.CANES.bit.CCE != 1 ); // Wait for CCE bit to be cleared.. ECanbShadow.CANBTC.all = 0; #if (CPU_FRQ_150MHZ) // CPU_FRQ_150MHz is defined in DSP2833x_Examples.h /* The following block for all 150 MHz SYSCLKOUT (75 MHz CAN clock) - default. Bit rate = 1 Mbps See Note at end of file */ ECanbShadow.CANBTC.bit.BRPREG = 4; ECanbShadow.CANBTC.bit.TSEG2REG = 2; ECanbShadow.CANBTC.bit.TSEG1REG = 10; #endif #if (CPU_FRQ_100MHZ) // CPU_FRQ_100MHz is defined in DSP2833x_Examples.h /* The following block is only for 100 MHz SYSCLKOUT (50 MHz CAN clock). Bit rate = 1 Mbps See Note at end of file */ ECanbShadow.CANBTC.bit.BRPREG = 4; ECanbShadow.CANBTC.bit.TSEG2REG = 1; ECanbShadow.CANBTC.bit.TSEG1REG = 6; #endif ECanbShadow.CANBTC.bit.SAM = 1; ECanbRegs.CANBTC.all = ECanbShadow.CANBTC.all; ECanbShadow.CANMC.all = ECanbRegs.CANMC.all; ECanbShadow.CANMC.bit.CCR = 0 ; // Set CCR = 0 ECanbRegs.CANMC.all = ECanbShadow.CANMC.all; ECanbShadow.CANES.all = ECanbRegs.CANES.all; do { ECanbShadow.CANES.all = ECanbRegs.CANES.all; } while(ECanbShadow.CANES.bit.CCE != 0 ); // Wait for CCE bit to be cleared.. /* Disable all Mailboxes */ ECanbRegs.CANME.all = 0; // Required before writing the MSGIDs EDIS; } #endif // if DSP28_ECANB //--------------------------------------------------------------------------- // Example: InitECanGpio: //--------------------------------------------------------------------------- // This function initializes GPIO pins to function as eCAN pins // // Each GPIO pin can be configured as a GPIO pin or up to 3 different // peripheral functional pins. By default all pins come up as GPIO // inputs after reset. // // Caution: // Only one GPIO pin should be enabled for CANTXA/B operation. // Only one GPIO pin shoudl be enabled for CANRXA/B operation. // Comment out other unwanted lines. void InitECanGpio(void) { InitECanaGpio(); #if (DSP28_ECANB) InitECanbGpio(); #endif // if DSP28_ECANB } void InitECanaGpio(void) { EALLOW; /* Enable internal pull-up for the selected CAN pins */ // Pull-ups can be enabled or disabled by the user. // This will enable the pullups for the specified pins. // Comment out other unwanted lines. GpioCtrlRegs.GPAPUD.bit.GPIO30 = 0; // Enable pull-up for GPIO30 (CANRXA) // GpioCtrlRegs.GPAPUD.bit.GPIO18 = 0; // Enable pull-up for GPIO18 (CANRXA) GpioCtrlRegs.GPAPUD.bit.GPIO31 = 0; // Enable pull-up for GPIO31 (CANTXA) // GpioCtrlRegs.GPAPUD.bit.GPIO19 = 0; // Enable pull-up for GPIO19 (CANTXA) /* Set qualification for selected CAN pins to asynch only */ // Inputs are synchronized to SYSCLKOUT by default. // This will select asynch (no qualification) for the selected pins. GpioCtrlRegs.GPAQSEL2.bit.GPIO30 = 3; // Asynch qual for GPIO30 (CANRXA) // GpioCtrlRegs.GPAQSEL2.bit.GPIO18 = 3; // Asynch qual for GPIO18 (CANRXA) /* Configure eCAN-A pins using GPIO regs*/ // This specifies which of the possible GPIO pins will be eCAN functional pins. GpioCtrlRegs.GPAMUX2.bit.GPIO30 = 1; // Configure GPIO30 for CANRXA operation // GpioCtrlRegs.GPAMUX2.bit.GPIO18 = 3; // Configure GPIO18 for CANRXA operation GpioCtrlRegs.GPAMUX2.bit.GPIO31 = 1; // Configure GPIO31 for CANTXA operation // GpioCtrlRegs.GPAMUX2.bit.GPIO19 = 3; // Configure GPIO19 for CANTXA operation EDIS; } #if (DSP28_ECANB) void InitECanbGpio(void) { EALLOW; /* Enable internal pull-up for the selected CAN pins */ // Pull-ups can be enabled or disabled by the user. // This will enable the pullups for the specified pins. // Comment out other unwanted lines. GpioCtrlRegs.GPAPUD.bit.GPIO8 = 0; // Enable pull-up for GPIO8 (CANTXB) // GpioCtrlRegs.GPAPUD.bit.GPIO12 = 0; // Enable pull-up for GPIO12 (CANTXB) // GpioCtrlRegs.GPAPUD.bit.GPIO16 = 0; // Enable pull-up for GPIO16 (CANTXB) // GpioCtrlRegs.GPAPUD.bit.GPIO20 = 0; // Enable pull-up for GPIO20 (CANTXB) GpioCtrlRegs.GPAPUD.bit.GPIO10 = 0; // Enable pull-up for GPIO10 (CANRXB) // GpioCtrlRegs.GPAPUD.bit.GPIO13 = 0; // Enable pull-up for GPIO13 (CANRXB) // GpioCtrlRegs.GPAPUD.bit.GPIO17 = 0; // Enable pull-up for GPIO17 (CANRXB) // GpioCtrlRegs.GPAPUD.bit.GPIO21 = 0; // Enable pull-up for GPIO21 (CANRXB) /* Set qualification for selected CAN pins to asynch only */ // Inputs are synchronized to SYSCLKOUT by default. // This will select asynch (no qualification) for the selected pins. // Comment out other unwanted lines. GpioCtrlRegs.GPAQSEL1.bit.GPIO10 = 3; // Asynch qual for GPIO10 (CANRXB) // GpioCtrlRegs.GPAQSEL1.bit.GPIO13 = 3; // Asynch qual for GPIO13 (CANRXB) // GpioCtrlRegs.GPAQSEL2.bit.GPIO17 = 3; // Asynch qual for GPIO17 (CANRXB) // GpioCtrlRegs.GPAQSEL2.bit.GPIO21 = 3; // Asynch qual for GPIO21 (CANRXB) /* Configure eCAN-B pins using GPIO regs*/ // This specifies which of the possible GPIO pins will be eCAN functional pins. GpioCtrlRegs.GPAMUX1.bit.GPIO8 = 2; // Configure GPIO8 for CANTXB operation // GpioCtrlRegs.GPAMUX1.bit.GPIO12 = 2; // Configure GPIO12 for CANTXB operation // GpioCtrlRegs.GPAMUX2.bit.GPIO16 = 2; // Configure GPIO16 for CANTXB operation // GpioCtrlRegs.GPAMUX2.bit.GPIO20 = 3; // Configure GPIO20 for CANTXB operation GpioCtrlRegs.GPAMUX1.bit.GPIO10 = 2; // Configure GPIO10 for CANRXB operation // GpioCtrlRegs.GPAMUX1.bit.GPIO13 = 2; // Configure GPIO13 for CANRXB operation // GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 2; // Configure GPIO17 for CANRXB operation // GpioCtrlRegs.GPAMUX2.bit.GPIO21 = 3; // Configure GPIO21 for CANRXB operation EDIS; } #endif // if DSP28_ECANB /* Note: Bit timing parameters must be chosen based on the network parameters such as the sampling point desired and the propagation delay of the network. The propagation delay is a function of length of the cable, delay introduced by the transceivers and opto/galvanic-isolators (if any). The parameters used in this file must be changed taking into account the above mentioned factors in order to arrive at the bit-timing parameters suitable for a network. */