UART Modules
Freescale Semiconductor
26-5
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
26.3.1
UART Mode Registers 1 (UMR1n)
The UMR1
n
registers control UART module configuration. UMR1
n
can be read or written when the mode
register pointer points to it, at RESET or after a
RESET
MODE
REGISTER
POINTER
command using
UCR
n
[MISC]. After UMR1
n
is read or written, the pointer points to UMR2
n
.
IPSBAR
Offset:
0x00_0200 (UMR10)
0x00_0240 (UMR11)
0x00_0280 (UMR12)
Access: User read/write
7
6
5
4
3
2
1
0
R
RXRTS
RXIRQ/
FFULL
ERR
PM
PT
B/C
W
Reset:
0
0
0
0
0
0
0
0
1
After UMR1n is read or written, the pointer points to UMR2n
Figure 26-3. UART Mode Registers 1 (UMR1n)
Table 26-3. UMR1n Field Descriptions
Field
Description
7
RXRTS
Receiver request-to-send. Allows the URTSn output to control the UCTSn input of the transmitting device to prevent
receiver overrun. If the receiver and transmitter are incorrectly programmed for URTSn control, URTSn control is
disabled for both. Transmitter RTS control is configured in UMR2n[TXRTS].
0 The receiver has no effect on URTSn.
1 When a valid start bit is received, URTSn is negated if the UART's FIFO is full. URTSn is reasserted when the
FIFO has an empty position available.
6
RXIRQ/
FFULL
Receiver interrupt select.
0 RXRDY is the source generating interrupt or DMA requests.
1 FFULL is the source generating interrupt or DMA requests.
5
ERR
Error mode. Configures the FIFO status bits, USRn[RB,FE,PE].
0 Character mode. The USRn values reflect the status of the character at the top of the FIFO. ERR must be 0 for
correct A/D flag information when in multidrop mode.
1 Block mode. The USRn values are the logical OR of the status for all characters reaching the top of the FIFO since
the last
RESET
ERROR
STATUS
command for the UART was issued. See
.”
4–3
PM
Parity mode. Selects the parity or multidrop mode for the UART. The parity bit is added to the transmitted character,
and the receiver performs a parity check on incoming data. The value of PM affects PT, as shown below.
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60