Specifications

Serial Communications (82050)
Serial Data Format
The ACC supports asynchronous data transfers. The format for the
asynchronous data includes start, stop, and optional parity bits as well
as five, six, seven, or eight data bits. This is illustrated in Figure 11-9.
Marking
Start
Bit
7 or 8 Data Bits
Asynchronous Data Format
Optional
Parity Bit
1 or 2
Stop
Bits
Marking
Start
Bit
Optional
Parity
Bit
1 or 2
Stop
Bits7 or 8 Data Bits
Break Sequence Format
Figure 11–9. ACC Serial Data Format.
The TxD signal is in the "mark" state when data is not being
transmitted. The start bit indicates the beginning of the serial data or
character bits. The parity bit is optionally inserted during transmission
and monitored during reception to test data integrity. The stop bit
flags the end of the serial data.
The format for the break sequence is also shown in Figure 11-9. The
transmission of the break sequence is programmed in the Line Control
register, and the reception of the break sequence is flagged in the Line
Status register.
11-21