Datasheet

14-10 MCF5307 User’s Manual
Register Descriptions
6–4
MISC Field (This field selects a single command.)
000
NO COMMAND —
001
RESET MODE
REGISTER POINTER
Causes the mode register pointer to point to UMR1n.
010
RESET RECEIVER Immediately disables the receiver, clears USRn[FFULL,RxRDY], and reinitializes
the receiver FIFO pointer. No other registers are altered. Because it places the
receiver in a known state, use this command instead of
RECEIVER DISABLE when
reconfiguring the receiver.
011
RESET
TRANSMITTER
disables the transmitter and clears USRn[TxEMP,TxRDY]. No other registers
are altered. Because it places the transmitter in a known state, use this
command instead of
TRANSMITTER DISABLE when reconfiguring the transmitter.
100
RESET ERROR
STATUS
lears USRn[RB,FE,PE,OE]. Also used in block mode to clear all error bits after a
data block is received.
101
RESET BREAK–
CHANGE INTERRUPT
Clears the delta break bit, UISRn[DB].
110
START BREAK Forces TxD low. If the transmitter is empty, the break may be delayed up to one
bit time. If the transmitter is active, the break starts when character transmission
completes. The break is delayed until any character in the transmitter shift
register is sent. Any character in the transmitter holding register is sent after the
break. The transmitter must be enabled for the command to be accepted. This
command ignores the state of CTS
.
111
STOP BREAK Causes TxD to go high (mark) within two bit times. Any characters in the
transmitter buffer are sent.
3–2
TC Field (This field selects a single command)
00
NO ACTION TAKEN Causes the transmitter to stay in its current mode: if the transmitter is enabled, it
remains enabled; if the transmitter is disabled, it remains disabled.
01
TRANSMITTER
ENABLE
Enables operation of the channel’s transmitter. USRn[TxEMP,TxRDY] are set. If
the transmitter is already enabled, this command has no effect.
10
TRANSMITTER
DISABLE
Terminates transmitter operation and clears USRn[TxEMP,TxRDY]. If a character
is being sent when the transmitter is disabled, transmission completes before the
transmitter becomes inactive. If the transmitter is already disabled, the command
has no effect.
11 — Reserved, do not use.
Table 14-6. UCRn Field Descriptions (Continued)
Bits Value Command Description
Fr
eescale S
emiconduct
or
, I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
nc...