Advanced use case doing port access

In this case we will read out the pins from one whole port and write the read value to another port.

Setup steps

Example code

#define IN_PORT  IOPORT_PORTA
#define OUT_PORT IOPORT_PORTB
#define MASK     0x00000060
 
ioport_init();
 
ioport_set_port_dir(IN_PORT, MASK, IOPORT_DIR_INPUT);
ioport_set_port_dir(OUT_PORT, MASK, IOPORT_DIR_OUTPUT);

Workflow

1. It's useful to give the ports symbolic names:

   • #define IN_PORT  IOPORT_PORTA
     #define OUT_PORT IOPORT_PORTB

   • Note

     The port names differ between architectures:

     • MEGA_RF, MEGA and XMEGA: There are predefined names for ports: IOPORT_PORTA, IOPORT_PORTB ...
     • UC3: Use the index value of the different IO blocks: 0, 1 ...
     • SAM: There are predefined names for ports: IOPORT_PIOA, IOPORT_PIOB ...

2. Also useful to define a mask for the bits to work with:

   • #define MASK     0x00000060 

3. Initialize the ioport service. This typically enables the IO module if needed.

   • ioport_init(); 

4. Set one of the ports as input:

   • ioport_set_pin_dir(IN_PORT, MASK, IOPORT_DIR_INPUT); 

5. Set the other port as output:

   • ioport_set_pin_dir(OUT_PORT, MASK, IOPORT_DIR_OUTPUT); 

Usage steps

Example code

ioport_port_mask_t value;
 
value = ioport_get_port_level(IN_PORT, MASK);
ioport_set_port_level(OUT_PORT, MASK, value);

Workflow

1. Define a variable for port date storage:

   • ioport_port_mask_t value; 

2. Read out from one port:

   • value = ioport_get_port_level(IN_PORT, MASK); 

3. Put the read data out on the other port:

   • ioport_set_port_level(OUT_PORT, MASK, value);