Peripheral Simulation

For Atmel AT8xC5122 — Smart Card Interface Hardware Configuration

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.

SmartCard Hardware Interface Dialog

This dialog (available from the Peripherals menu) displays the status of the SmartCard Hardware Interface.

• System Clock: This value specifies the frequency of the external oscillator. It corresponds to the virtual register XTAL.
• Main Card Clock: Specifies the frequency that is supplied to the main smart card.
• Alternate Card Clock: Specifies the frequency that is supplied to the alternate smart card
• div. factor for ser. interface: Specifies the clock prescaler for one 'Elementary Timing Unit (ETU)' for the software ISO interface (not for UART). It corresponds to the virtual register SDIV.
• Resulting Baudrate: Displays the resulting baudrate (= XTAL / SDIV) for the software ISO interface.
• Parity: Selects the simulated parity for the software ISO interface. It corresponds to the virtual register USE_PAR.
• Use serial Hardware Interface: If selected, the serial in/output is directed to a COM port of the PC. If not selected, the serial in/output goes to the serial window. It corresponds to the virtual register HWI.
• Serial Interface: Specifies the COM port of the PC for serial in/output. It corresponds to the virtual register USE_COM.
• Baudrate: Specifies the baudrate for the COM port of the PC. It corresponds to the virtual register USE_BR.
• Parity: Specifies the parity for the COM port of the PC. It corresponds to the virtual register USE_PAR.
• Clock (DTR): Displays the level of the DTR handshake line of the COM port of the PC. This line is used to switch on/off the clock generator of the smartcard interface.
• Power (RTS): Displays the level of the RTS handshake line of the COM port of the PC. This line is used to switch on/off the power supply of the smartcard interface.

HWI VTREG
Data Type: unsigned char

The HWI VTREG specifies whether the hardware interface should be used or not. The value 0 means that the serial input/output is simulated in the serial window. The value 1 means that the bytes are sent and received through the serial interface of the PC. With a suitable interface, the simulator can be used to interface to a chip card. The HWI VTREG can be used in simulator initialization script for automatic tests:

USE_BR  = 9600    /* select 9600 baud          */
USE_COM = 1       /* use COM2                  */
HWI     = 1       /* select hardware interface */

SDIV VTREG
Data Type: unsigned int

The SDIV VTREG specifies the clock prescaler for one 'Elementary Timing Unit (ETU)' when the serial transmission/reception is done by software. One ETU is the duration of one bit on the smartcard ISO interface. Together with XTAL, the baudrate is calculated as ‘baud = xtal / sdiv’. The default value is 372. SDIV is not significant when the on-chip UART is used.

USE_BR VTREG
Data Type: unsigned long

The USE_BR VTREG specifies the baudrate of the COM port of the PC when HWI it set to 1. This baudrate and the one from the 'Software ISO Interface' can be different. The default value is -1 (=0xFFFFFFFF). This value specifies that the baudrate of the COM port of the PC follows the selected on-chip UART baudrate.

USE_COM VTREG
Data Type: unsigned char

The USE_COM VTREG specifies the number of the COM port of the PC which is used when HWI is set to 1. The default value 1 means that COM1 is used. Values from 1 to 8 are allowed.

USE_PAR VTREG
Data Type: unsigned char

The USE_PAR VTREG specifies the parity-mode of the COM port of the PC and the parity of the software ISO interface.

0 = even parity
1 = odd parity
2 = no parity

XTAL VTREG
Data Type: unsigned long

The XTAL VTREG contains the frequency of the oscillator (in Hertz) used to drive the microcontroller. The value is automatically set from the value specified in Project Options - Options for Target. However, you may change the value of XTAL using the command window. For example:

XTAL=12000000

You may also output the current value of XTAL using the following:

XTAL

XTAL may be used in calculations to synchronize external scripts with the simulated microcontroller.