Specifications

Serial Communications (82050)
Transmit and Receive Buffer
The Transmit Buffer, Receive Buffer, and Interrupt Enable registers
share the same addresses as the Divisor Latch. Since the Divisor
Latch is programmed only once during system initialization, this
should cause no problems. During system initialization, the Divisor
Latch is selected by programming the Divisor Latch Access Bit of the
Line Control register. The Divisor Latch is then initialized to select
the appropriate baud rate, and the Divisor Latch Access Bit is
reprogrammed to enable the Transmit Buffer, Receive Buffer, and
Interrupt Enable register for serial communications.
Line Contr
ol
The main function of the Line Control register, shown in Figure 11-2,
is to define the format of the serial data.
The Word Length Select (WLS) field defines the character length, as
shown in Table 11-2.
Table 11-2
Serial Character Length.
Bit 1 Bit 0 Character Length
0 0 5 bits
0 1 6 bits
1 0 7 bits
1 1 8 bits
11-8