ADSP-214xx SHARC Processor Hardware Reference
20-9
UART Port Controller
transmitter transmits the
TX9D
bit instead of the parity bit. During 9-bit
transmission mode, the parity select controls and the word length select do
not have any effect.
For the receiver, set the
RX9
bit in the
UART_MODE
register and the
UAEN
bit
in the
UAC_RXCTL
register (to enable reception). Set the address enable bit
(
UARTAEN
) to enable address detection.
If the received ninth bit is high, the received word is shifted from the
RSR
register to the
UART_RBR
buffer which generates an interrupt. Read the
UART_RBR
buffer to find out if the device is being addressed. If the device is
being addressed, the address enable (
UARTAEN
bit) is cleared to allow data
and address bytes to be read into the receive buffer.
During the 9 bit transmission mode parity has to be calculated in software
to detect errors. The reception may be stopped when the receiver receives
another address which is different from its own.
In 9-bit mode, the address detect interrupt can be generated whenever the
receiver gets an address word, irrespective of the packing mode. This helps
programs respond to an address word immediately. The program is
expected to take into account these features when using packed mode.
Packed Mode
Programs must use care when using the packing feature in 9-bit
transmission mode.
• Programs should write the
UARTPKSYN
bit (bit 1) with a 1 each time
an address is received. This starts the reception of the following
data from the lower half-word of the
UARTRBR
register.
• The address-detect interrupt is generated whenever the UART
receiver receives an address, irrespective of the packing. The DR bit
in the
UARTLSR
register can be used to discover whether the address
is in the lower (
DR
= 0) or higher half-word (
DR
= 1). The LSR reg-
ister must be read before reading the
UARTRBR
register, because the
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Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...