UART Modules
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
23-5
Preliminary
23.3.1
UART Mode Registers 1 (UMR1
n
)
The UMR1
n
registers control 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 UMR1
n
is read or written, the pointer points to UMR2
n
Figure 23-3. UART Mode Registers 1 (UMR1
n
)
Table 23-3. UMR1
n
Field Descriptions
Field
Description
7
RXRTS
Receiver request-to-send. Allows the URTS
n
output to control the UCTS
n
input of the transmitting device to prevent
receiver overrun. If the receiver and transmitter are incorrectly programmed for URTS
n
control, URTS
n
control is
disabled for both. Transmitter RTS control is configured in UMR2
n
[TXRTS].
0 The receiver has no effect on URTS
n
.
1 When a valid start bit is received, URTS
n
is negated if the UART's FIFO is full. URTS
n
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, USR
n
[RB,FE,PE].
0 Character mode. The USR
n
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 USR
n
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.