Specifications

Serial Communications (16C452)
Bit 2 Bit 2 specifies the number of stop bits in the
transmitted or received serial character. If bit 2 is a
logical 0, one stop bit is generated or checked in the
transmit or receive data, respectively. If bit 2 is a
logical 1 when a 5-bit word length is selected via
bits 0 and 1, 1
1
⁄2 stop bits are generated or checked. If
bit 2 is a logical 1 when either a 6-, 7-, or 8-bit word
length is selected, two stop bits are generated or
checked. The receiver checks for two stop bits if
programmed.
Bit 3 This bit is the Parity Enable bit. When bit 3 is a
logical 1, a parity bit is generated (transmit data) or
checked (receive data) between the last data word bit
and stop bit of the serial data.
Bit 4 This is the Even Parity Select bit. When bit 3 is a
logical 1 and bit 4 is a logical 0, an odd number of
logical 1s is transmitted or checked in the data word
bits and parity bit. When bit 3 is a logical 1 and bit 4
is a logical 1, an even number of bits is transmitted or
checked.
Bit 5 Bit 5 is the Stick Parity bit. When bit 3 is a logical 1
and bit 5 is a logical 1, the parity bit is transmitted
and then detected by the receiver in the opposite state
indicated by bit 4. This allows you to force parity to a
known state and allows the receiver to check the
parity bit in a known state.
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