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116
Serial Communication with the UART
select the parity mode (no parity bit, even parity bit, odd parity bit, parity bit always
one, and parity bit always zero, respectively).
The peripheral clock is the same as the processor clock and can be obtained by using
SysCtlClockGet().
Returns: None
• UARTCharGet Waits for a character from the specified port.
Prototype: long UARTCharGet(unsigned long ulBase)
Parameters: ulBase is the base address of the UART port.
Description: This function gets a character from the receive FIFO for the specified
port. If there are no characters available, this function waits until a character is
received before returning.
Returns: Returns the character read from the specified port, cast as a long.
• UARTCharPut Waits for a character from the specified port.
Prototype: void UARTCharGet(unsigned long ulBase, unsigned char ucData)
Parameters: ulBase is the base address of the UART port. ucData is the character
to be transmitted.
Description: This function sends the character ucData to the transmit FIFO for the
specified port. If there is no space available in the transmit FIFO, this function waits
until there is space available before returning.
Returns: None
10.4 Experiment 13
10.4.1
Objective
To control the intensity of LED, LD5, connected on PC7 using software PWM using
parameters received over UART. Configuration of the UART is 115200, 8, N, 1.
10.4.2
Program Flow
This experiment allows us to control the intensity of an LED using parameters received over
UART. The block diagram is shown in Figure 10.6. The parameter is a number between 0
to 10, where 0 signifies the least intensity and 10 signifies the highest intensity. Drawing on
the algorithm from the previous experiment with the addition of software PWM, the new
algorithm is: