Queued Serial Multi-Channel Module
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
15-49
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
Field
—
TDRE
TC
RDRF RAF
IDLE
OR
NF
FE
PF
SRESET
0000_000
1
1
0
0
0
0
0
0
0
Addr
0x30 500C; 0x30 5024
Figure 15-28. SCIx Status Register (SCxSR)
Table 15-26. SCxSR Bit Descriptions
Bits
Name
Description
0:6
—
Reserved
7
TDRE
Transmit data register empty. TDRE is set when the byte in TDRx is transferred to the transmit
serial shifter. If this bit is zero, the transfer is yet to occur and a write to TDRx will overwrite the
previous value. New data is not transmitted if TDRx is written without first clearing TDRE.
0 Transmit data register still contains data to be sent to the transmit serial shifter.
1 A new character can now be written to the transmit data register.
For transmit queue operation, this bit should be ignored by software.
8
TC
Transmit complete. TC is set when the transmitter finishes shifting out all data, queued preambles
(mark/idle-line), or queued breaks (logic zero).
0 SCI transmitter is busy.
1 SCI transmitter is idle.
For transmit queue operation, TC is cleared when SCxSR is read with TC set, followed by a write
to SCTQ[0:15].
9
RDRF
Receive data register full. RDRF is set when the contents of the receive serial shifter are
transferred to register RDRx. If one or more errors are detected in the received word, the
appropriate flag(s) (NF, FE, or PF) are set within the same clock cycle.
0 Receive data register is empty or contains previously read data.
1 Receive data register contains new data.
For receiver queue operation, this bit should be ignored by software.
10
RAF
Receiver active flag. RAF indicates whether the receiver is busy. This flag is set when the receiver
detects a possible start bit and is cleared when the chosen type of idle line is detected. RAF can
be used to reduce collisions in systems with multiple masters.
0 SCI receiver is idle.
1 SCI receiver is busy.
11
IDLE
Idle line detected. IDLE is set when the receiver detects an idle-line condition (reception of a
minimum of 10 or 11 consecutive ones as specified by ILT in SCCxR1). This bit is not set by the
idle-line condition when RWU in SCCxR1 is set. Once cleared, IDLE is not set again until after
RDRF is set (after the line is active and becomes idle again). If a break is received, RDRF is set,
allowing a subsequent idle line to be detected again.
Under certain conditions, the IDLE flag may be set immediately following the negation of RE in
SCCxR1. System designs should ensure this causes no detrimental effects.
0 SCI receiver did not detect an idle-line condition.
1 SCI receiver detected an idle-line condition.
For receiver queue operation, IDLE is cleared when SCxSR is read with IDLE set, followed by a
read of SCRQ[0:15].
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...