Peripheral Simulation

For Infineon C505CA-4E — CAN Controller

Simulation support for this peripheral or feature is comprised of:

• Dialog boxes which display and allow you to change peripheral configuration.
• VTREGs (Virtual Target Registers) which support I/O with the peripheral.

These simulation capabilities are described below.

CAN Controller Configuration Dialog

The Controller Area Network (CAN) Controller Configuration tab configures the on-chip CAN controller. The CAN controller provides storage for up to 15 message objects which can be a maximum of 8 bytes long.

Power Group

• CSWO (CAN Switch Off) is set if the CAN controller is disabled. If reset, the CAN controller is enabled (default after a reset).

Control Group

• CR (CAN Control Register) contains the Test mode (TEST), Initialization (INIT) and Configuration Change Enable (CCE) control bits.
• TEST (Test Mode) is used only during chip production testing. This bit must always be reset when writing to the CAN Control Register.
• INIT (Initialization) is set to to perform a software initialization the CAN Controller.
• CCE (Configuration Change enable) is set to allow the microcontroller access to the bit timing register.

Bit Timing Group

• BTR0 (CAN Bit Timing Register Low) contains the Synchronization Jump Width (SJW) and Baud Rate Prescaler (BRP) settings.
• BTR1 (CAN Bit Timing Register High) contains the Time Segment Before Sample Point (TSEG1) and Time Segment After Sample Point (TSEG2) settings.
• CMOD (CAN Controller Prescaler Selection) is set to disable the divide by 2 prescaler. If reset, enables the divide by 2 prescaler.
• Baudrate displays the current baud rate based on the Baud Rate Prescaler (BRP) value.
• BRP (Baud Rate Prescaler) contains the value-1 to be divided into the oscillator frequency to generate the desired baud rate.
• TSEG1 (Time Segment Before Sample Point) contains the number of time segments (from 1 to 7) within 1 bit time to wait before sampling 1 bit of data.
• TSEG2 (Time Segment After Sample Point) contains the number of time segments (from 2 to 15) within 1 bit time to wait after sampling 1 bit of data.
• SJW (Synchronization Jump Width) contains the maximum number of time segments 1 bit time may be reduced or lengthened during message re-synchronization.

Status Group

• SR (CAN Status Register SR) contains the Busoff (BOFF), Error Warning Status (EWRN), Received Message Successfully (RXOK), Transmitted Message Successfully (TXOK) and Last Error Code (LEC) status information.
• LEC (Last Error Code) displays the last error code reported on the CAN bus.
• TXOK (Transmitted Message Successfully) is set when the last message was sent with no errors.
• RXOK (Received Message Successfully) is set when a message was received with no errors.
• EWRN (Error Warning Status) is set when the error counter limit reaches 96.
• BOFF (Busoff Status) is set when the bus off state of the CAN Controller is set.

Global Mask Group

• GMS (Global Mask Status) contains the 11-bit identifier mask. Bits 0-4 of the upper byte of this register are always set. Disable the Extended Identifier (XTD) bit to use this mask.
• UGML (CAN Upper Global Mask Long Register) contains bits 28-13 of the 29-bit identifier mask. Enable the Extended Identifier (XTD) bit to use this mask.
• LGML (CAN Lower Global Mask Long Register) contains bits 12-0 of the 29-bit identifier mask. Enable the Extended Identifier (XTD) bit to use this mask. Bits 0-2 of the upper byte of this register are always reset.
• Mask(11-bit) displays the 11-bit identifier mask value.
• Mask(29-bit) displays the 29-bit identifier mask value.

Interrupts Group

• IR (CAN Interrupt Register) contains the identifier of a CAN interrupt request. If zero, no CAN interrupts are pending.
• IE (CAN Interrupt Enable) is set to allow the CAN controller to generate interrupts. If reset, the CAN controller cannot generate interrupts.
• SIE (CAN Status Change Interrupt Enable) is set to generate an interrupt when a message transfer completes, or when the controller detects a CAN bus error.
• EIE (CAN Error Interrupt Enable) is set to generate an interrupt when either Busoff (BOFF) or Error Warning Status (EWRN) status bits change.

Mask of Last Message (Channel 15) Group

• UMLM (Upper Mask of Last Message Register) holds bits 28-13 of the mask value used for the last incoming message.
• LMLM (Lower Mask of Last Message Register) holds bits 12-0 of the mask value used for the last incoming message.
• Mask (11-bit) displays the 11-bit last message mask.
• Mask (29-bit) displays the 29-bit last message mask.

CAN Controller - Channel Dialog

The Controller Area Network (CAN) Controller Channel tab displays and configures the channel settings for the 15 message channels on the on-chip CAN controller. The list box displays the current setting for each channel. Use the Select Channel group below the change channel settings.

Select Channel Group

• ID (Message Identifier) displays the 11-bit or 29-bit message identifier, depending on the state of the Extended Identifier (XTD) bit.
• XTD (Extended Identifier) is set if the message contains 29-bit identifiers, or reset if the message contains 11-bit identifiers.
• DIR (Message Direction) is set for transmitted messages, and reset for received messages.
• UAR (Upper Arbitration Register) contains bit 28-13 of the identifier mask used for bus arbitration.
• LAR (Lower Arbitration Register) contains bit 12-0 of the identifier mask used for bus arbitration.
• Length (Data Length) contains the length of the data in this message. Data can be from 0 to 8 bytes long.
• Data displays the data for this message in hexadecimal format.
• MSGVAL (Message Valid) is set when a message object is valid. Software resets this bit to indicate a message is no longer needed.
• INTPND (Interrupt Pending) is set when a message object generates an interrupt.
• RXIE (Receive Interrupt Enable) is set when a frame is received without error.
• TXIE (Transmit Interrupt Enable) is set when a frame is sent without error.
• NEWDAT (New Data) is set when the data portion of the message object is updated.
• MSGLST / CPUUPD (Message Lost / CPU Update) If receiving a message, this bit is set if the data portion of the message object is updated while the NEWDAT flag was set. This means the previously stored data was lost. If transmitting a message, the CPU sets this bit to indicate a message may not be transmitted at this time.
• TXRQ (Transmit Request) is set to indicate the CPU or remote node requested a message transmission, but not completed it.
• RMTPMD (Remote Pending) is set to indicate that the CAN controller received a requested for a message transmission, but it has not been transmitted. When this bit is set, the CAN controller sets TXRQ.

CANBx VTREG
Data Type: unsigned char

The CANBx VTREGs contains the eight bytes of the CAN message. CANB0 is the first byte, CANB1 is the second byte, and so on.

• When the simulated MCU transmits a CAN message, these VTREGs contain the message data bytes.
• To simulate a received CAN message, these VTREGs must be initialized with the message data bytes.

CANID VTREG
Data Type: unsigned long

The CANID VTREG specifies the ID of the CAN message.

• When the simulated MCU transmits a CAN message, this VTREG contains the message ID.
• To simulate a received CAN message, this VTREG must be initialized with the message ID.

CANIN VTREG
Data Type: unsigned char

The CANIN VTREG specifies the type of CAN message the simulated MCU will receive. The values 1-4 are used:

• 1: Message with 11-bit ID.
• 2: Message with 29-bit ID.
• 3: Message Request with 11-bit ID.
• 4: Message Request with 29-bit ID.

For example:

CANIN=2;  // Input a 29-bit ID message

The following debugger function shows how you can receive CAN messages into your application.

func void CAN_Send (unsigned char msgno) {

switch (msgno)
  {
  case 0:
    CANB0=' '; CANB1=' '; CANB2='K'; CANB3='E';
    CANB4='I'; CANB5='L'; CANB6=' '; CANB7=' ';
    CANL=8;
    break;

  case 1:
    CANB0='S'; CANB1='o'; CANB2='f'; CANB3='t';
    CANB4='w'; CANB5='a'; CANB6='r'; CANB7='e';
    CANL=8;
    break;

  default:
    CANB0='H'; CANB1='e'; CANB2='l'; CANB3='l';
    CANB4='o'; CANB5='!'; CANB6=' '; CANB7=' ';
    CANL=6;
    break;
  }

CANID = 456;
CANIN = 1;
}

CANL VTREG
Data Type: unsigned char

The CANL VTREG specifies the length of the CAN message in bytes.

• When the simulated MCU transmits a CAN message, this VTREG contains the number of bytes in the message.
• To simulate a received CAN message, this VTREG must be initialized with the number of bytes in the message.

CANOUT VTREG
Data Type: unsigned char

The CANOUT VTREG specifies the type of CAN message that was transmitted by the simulated MCU. The values 1-4 are used:

• 1: Message with 11-bit ID was sent.
• 2: Message with 29-bit ID was sent.
• 3: Message Request with 11-bit ID was sent.
• 4: Message Request with 29-bit ID was sent.

The following debugger signal function shows how you can monitor and report on CAN messages transmitted by your application.

signal void CAN_Recv (void) {
while (1)
  {
  wwatch(CANOUT);

  printf ("Received CAN Message\n");
  printf ("CAN ID %4.4lX (%u): ", CANID, (unsigned) CANL);
  printf ("%2.2X %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X ",
    (int)CANB0, (int)CANB1, (int)CANB2, (int)CANB3,
    (int)CANB4, (int)CANB5, (int)CANB6, (int)CANB7);
  printf ("\n");
  }
}