–39–

REV. 0

ADSP-2191M

Universal Asynchronous Receiver-Transmitter (UART) Port—Receive and Transmit Timing

Figure 23 describes UART port receive and transmit operations. The maximum baud rate is HCLK/16. As shown in Figure 23 there

is some latency between the generation internal UART interrupts and the external data operations. These latencies are negligible at

the data transmission rates for the UART.

Figure 23. UART Port—Receive and Transmit Timing

RXD

DATA(5–8)

INTERNAL

UART RECEIVE

INTERRUPT

UART RECEIVE BIT SET BY DATA STOP;

CLEARED BY FIFO READ

HCLK

(SAMPLE

CLOCK)

TXD

DATA(5–8)

STOP (1–2)

INTERNAL

UART TRANSMIT

INTERRUPT

UART TRANSMIT BIT SET BY PROGRAM;

CLEARED BY WRITE TO TRANSMIT

START

STOP

TRANSMIT

RECEIVE

AS DATA

WRITTEN TO

BUFFER