| Description: | Read I/O Byte. This function returns the byte read from an I/O port. |
| Returns: | Byte |
Usage:  |
Script or steady state. |
| Function Groups: | Memory I/O, Stream and Socket |
| Related to: | InWord | Out | OutWord |
| Format: |
In(Port) |
| Parameters: |
| Port |
| Required. Any numeric expression, which specifies which I/O port to read. Port must be in the range 0 to 65535 |
| Comments: | This function requires that the VTSIO driver be installed. Please refer to the topic, Communicating Directly With Hardware for more details. If In is used in a statement or an action trigger, it will be evaluated at a very fast rate. In is a high priority function, and should be used sparingly to avoid reducing overall system performance. |
Example:
reg = In(0x300);
This reads a byte from CPU input port 300 hex. If this statement appears in a script the read takes place when the script is executed. If this statement appears in steady state, it is updated very rapidly as a high-priority function.
