UART Application Testbench

This testbench verifies the interactive capabilities of the processor, specifically focusing on the UART Calculator application. Unlike the benchmark simulation, this testbench actively injects data and adheres to a strict handshaking protocol.

The send_uart Task

The core of this verification is the send_uart task, which automates the entry of complex commands. It constructs a 9-byte packet consisting of:

1. Command Byte: The ASCII character for the operation. (e.g., d for division. For the full list of commands, refer to the UART Calculator documentation.)
2. Operand 1 (4 bytes): The first 32-bit number.
3. Operand 2 (4 bytes): The second 32-bit number.

Handshaking Protocol

The task simulates a real UART controller by waiting for the CPU to acknowledge receipt of each byte before sending the next.

// Wait until CPU acknowledges (reads from UART_RX)
wait (UART_RX_ack == 1); 
UART_RX_valid = 0;
// Wait until CPU clears ack before sending next byte
wait (UART_RX_ack == 0);

Test Coverage

You are encouraged to extend tb_uart.v with additional test cases to verify specific scenarios. When adding new tests, please refer to the UART Calculator Command Reference to ensure the correct the command code is used.