Peripheral Simulation

For Atmel AT91M55800A — Digital/Analog Converter 1 (1 Channel)

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.

Digital/Analog Converter 1 Dialog

The Digital/Analog Converter 1 dialog displays and configures the D/A converter. The controls in this dialog are separated into several logical groups.

Control Group

• DAC1_CR (Control Register) displays and configures the D/A Converter control register.
• SWRST (Software Reset) button performs a softwar-triggered reset of the DAC.

Mode Group

• DAC1_CR (DAC Control Register) displays and configures the D/A Converter control register.
• RES (Resolution) transfers an 8-bit value to the convert registers, if set. 10-bit data is transferred in 16-bit format, if reset.
• TTRGSEL (Timer Trigger Selection) selects the hardware trigger source.
• TTRGEN (Timer Trigger Enable) enables data transfer synchronization using the timer trigger.

Data Holding & Output Group

• DAC1_DHR (Data Holding Register) displays the digital data to be converted.
• DAC1_DOR (Output Register) displays the digital data being converted.

Interrupt Mask & Status Group

• DAC1_IMR (Data Holding Register) holds the Data Ready for Conversion Interrupt Mask (DATRDY) setting.
• DATRDY (Data Ready for Conversion Interrupt Mask) enables the Data Ready for Conversion interrupt.
• DAC1_SR (Output Register) holds the Data Ready for Conversion (DATRDY) status.
• DATRDY (Data Ready for Conversion) is set when the Data Output Register (DAC1_DOR) receives the last data written to the Data Holding Register (DAC1_IMR).

Analog Output Group

• DA1 (Analog Output) displays the analog voltage value.

Reference Voltage

• DAVREF (Analog reference) configures the output voltage limit for DA1.

DAVREF VTREG
Data Type: float

The DAVREF VTREG sets the analog reference voltage for simulated D/A converters.

DAx VTREG
Data Type: float

The DAx VTREGs represent the analog output voltages for simulated D/A converters. If you have properly configured the analog outputs, the following commands (typed in the debugger's Command Window) display the voltages at each D/A output pin.

DA0  /* Output D/A Channel 0 value */
DA1  /* Output D/A Channel 1 value */

You may create a debugger signal function to process the voltage output on a D/A. The following signal function simulates a wire connecting D/A channel 0 to A/D channel 0. The value is copied 10 times per second.

signal void da_sig (void) {
  while (1) {
    AD0 = DA0;      /* Feed DA0 back into AD0 */
    swatch(0.1);    /* Sleep for 0.1 sec */
  }
}