UART Programming Model
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
20-29
20.6.3 SCI Status Register (SCISR)
SCISR can be read any time. A write has no meaning or effect.
SCISR
SCI Status Register
Offset 0x10
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
—
Type
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
TDRE
TC
RDRF IDLE
OR
NF
FE
PF
—
RAF
Type
R
R/W
R
Reset
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 20-11. SCISR Bit Descriptions
Name
Reset
Description
Settings
—
31–16
0
Reserved. Write to zero for future compatibility.
TDRE
15
1
Transmit Data Register Empty Flag
Set when the transmit shift register receives a character from
the SCI data register. When TDRE is 1, the transmit data
register (SCIDR) is empty and can receive a new value to
transmit. This flag can generate an interrupt request (refer to
Section 20.5).
Clear TDRE by reading TDRE and then writing to T[7–0] in
the SCIDR.
1
Character transferred to
transmit shift register;
transmit data register empty.
0
No character transferred to
transmit shift register.
TC
14
1
Transmit Complete Flag
Set low when there is a transmission in progress or when a
preamble or break character is loaded. TC is set high when
the TDRE flag is set and no data, preamble, or break
character is being transmitted. When TC is set, UTXD
becomes idle (logic 1). This flag can generate an interrupt
request (refer to Section 20.5).
Clear TC by reading TC and then writing to T[7–0] in the
SCIDR. TC is cleared automatically when data, preamble, or
break is queued and ready to be sent. Also, TC is cleared in
the event of a simultaneous set and clear of the TC flag
(transmission not complete).
1
No transmission in progress.
0
Transmission in progress.
RDRF
13
0
Receive Data Register Full Flag
Set when the data in the receive shift register transfers to the
SCI data register. This flag can generate an interrupt request
(refer to Section 20.5).
Clear RDRF by reading RDRF bit at SCISR and then reading
R[7–0] in the SCIDR.
Note:
Once the RDRF flag is cleared, after it is set by a
break or idle character, a valid frame must set the
RDRF flag before another break or idle character
can set it again.
1
Received data available in
SCI data register.
0
Data not available in SCI data
register.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...