Peripheral Simulation

For Analog Devices ADuC7020 — General Purpose Input/Output Port 0 (8-Bit)

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.

GPIO Port 0 Dialog

The GPIO Port 0 Dialog controls the direction of the general purpose port pins. You may use the following controls to select and configure the GPIO port settings.

GPIO Configuration & Data Group

• GP0DAT (Configuration and Data Register) contains the Direction, Output and At Reset settings.
• Direction bits are checked to configure a pin for output or reset for input.
• Output checkboxes represent the data bits output.
• At Reset checkboxes represent the state of the port pins after a reset.
• Input checkboxes show the value of the data on an input port.

I/O Pins Group

• The I/O Pins section allows you to manually set or clear individual pins for this port.

GPIO Control Group

• GP0CON (Control Register) controls the function of each pin for this port.
• P0.x (Port 0 - Pins 0-7) selects the function to be assigned to this pin from a drop-down list.

PORTx VTREG
Data Type: unsigned char

The PORTx VTREGs represent the I/O pins of the simulated MCU for Port 0, Port 1, and so on. PORT0 represents Port 0, PORT1 represents Port 1, 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,

PORT0

to obtain value corresponding to the set pins of Port 0. You may also change the input values of port pins by changing the value of the VTREG. For example,

PORT1=0xF0

sets the upper four port pins of Port 1 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:

PORT1 |=  0x01;  /* Set P1.0 Pin */
PORT2 &= ~0x10;  /* Clr P2.4 Pin */
PORT0 ^=  0x08;  /* Toggle P0.3 Pin */