Peripheral Simulation

For Atmel AT91M55800A — Parallel I/O Controller A (30 I/O Lines)

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.

Parallel I/O Controller A Dialog

The PIO Dialog box allows you to configure the parallel I/O port using checkboxes. Controls in this dialog are presented in groups which are described below.

PIO/Input Filter/Output/Data/Multi Driver

• The PIOA_PSR check boxes indicate which pins are controlled by the associated peripheral (0-unchecked) and which pins are controlled by the PIO (1-checked). Changing the values of these check boxes changed the values of the PIOA_PER and PIOA_PDR peripheral registers.
• The PIOA_IFSR check boxes indicate that glitch filtering is enabled (1-checked) for the corresponding pin. Changing these check boxes writes to the PIOA_IFER or PIOA_IFDR peripheral registers.
• The PIOA_OSR check boxes indicate the output status (0-unchecked for input, 1-checked for output) of the corresponding pin. Changing these check boxes writes to the PIOA_OER or PIOA_ODR peripheral registers.
• The PIOA_ODSR check boxes indicate the output value for each port pin. Changing these check boxes writes to the PIOA_SODR or PIOA_CODR peripheral registers.
• The PIOA_MDSR check boxes indicate whether each port pin is open drain (1-checked) or not (0-unchecked). Changing these check boxes writes to the PIOA_MDER or PIOA_MDDR peripheral registers.

Pin Data Status

• The PIOA_PDSR check boxes indicate the pin data status of the pins on the simulated MCU.

I/O Pins

• The Pins check boxes indicate the states of the pins on the simulated MCU. When used as outputs, these have the same value as the PIOA_ODSR check boxes. When used as inputs you may set the level of the input pin to high (1) or low (0).

Interrupt Mask & Status

• The PIOA_IMR check boxes indicate the interrupts enabled for each corresponding pin. Changing these check boxes writes to the PIOA_IER or PIOA_IDR peripheral registers.
• The PIOA_ISR check boxes allow you to view the interrupt status registers for the PIOA pins.

PORTx VTREG
Data Type: unsigned long

The PORTx VTREGs represent the I/O pins of the simulated MCU for Port A, Port B, and so on. PORTA represents Port A, PORTB represents Port B, etc. You may read PORTx to determine the state of the output pins of that port. For example, in the command window you may type,

PORTA

to obtain value corresponding to the set pins of Port A. You may also change the input values of port pins by changing the value of the VTREG. For example,

PORTA=0x000000F0

sets the upper four port pins of Port A to a value of 1 and all other port pins to a value of 0. You may use the bitwise operators AND(&), OR(|) and XOR(^) to change individual bits of the PORTx VTREGs. For example:

PORTA |=  0x00000001;  /* Set PA0 Pin */
PORTB &= ~0x00000200;  /* Clr PB9 Pin */
PORTA ^=  0x00800000;  /* Toggle PA23 Pin */