UARTs
LH79524/LH79525 User’s Guide
16-16
Version 1.0
4
FEN
FIFO Enable Buffers
This bit not only enables and disables the FIFO buffers,
but also controls the mode. When the FIFO is enabled, it is used to buffer receive
and transmit data. When the FIFO is disabled, the UART is in Character Mode,
using just one line in the FIFO to store a single character.
1 = Enables transmit and receive FIFO buffers (FIFO Mode).
0 = FIFOs are disabled (Character Mode); that is, the FIFOs become
one-byte-deep holding registers.
3
STP2
Frame Stop Bits
This bit sets the number of Stop bits.
1 = Two Stop bits are transmitted at the end of the frame. The receive logic does
not check for two Stop bits being received.
0 = One Stop bit
2
EPS
Even Parity Select
Bits [7], [2], and [1] work together to set up the parity. See
1
PEN
Parity Enable
Bits [7], [2], and [1] work together to set up the parity. See
0
BRK
SEND BREAK
This bit commands the UART to enter a Break condition. This
bit must be asserted for at least one complete frame transmission time in order
to generate a break condition. The transmit FIFO contents remain unaffected
during a break condition. For normal use, this bit must be cleared to 0.
1 = A LOW level is continually output on the UARTTXD output, after completing
transmission of the current character
0 = No Break
Table 16-21. Truth Table for 9BIT, SPS, EPS, and PEN bits
9BIT
SPS
EPS
PEN
RESULTANT PARITY BIT (TRANSMITTED OR CHECKED)
0
X
X
0
Not transmitted or checked
0
0
0
1
Odd parity
0
0
1
1
Even parity
0
1
0
1
1
0
1
1
1
0
1
X
X
X
For transmission, ADDRESS TRANSMIT is transmitted as
the parity bit for the frame. If the received parity bit = 1, then the
PARITY-ERROR/ADDRESS RECEIVED error is generated.
Table 16-20. UARTLCR_H Fields (Cont’d)
BIT
NAME
DESCRIPTION