Serial Communication Interface (SCI)
MCF51CN128 Reference Manual, Rev. 6
13-11
Freescale Semiconductor
13.2.5
SCI Status Register 2 (SCIxS2)
This register contains one read-only status flag.
1
FE
Framing Error Flag. FE is set at the same time as RDRF when the receiver detects a logic 0 where the stop bit
was expected. This suggests the receiver was not properly aligned to a character frame. To clear FE, read
SCIxS1 with FE set and then read the SCI data register (SCIxD).
0 No framing error detected. This does not guarantee the framing is correct.
1 Framing error.
0
PF
Parity Error Flag. PF is set at the same time as RDRF when parity is enabled (PE = 1) and the parity bit in the
received character does not agree with the expected parity value. To clear PF, read SCIxS1 and then read the
SCI data register (SCIxD).
0 No parity error.
1 Parity error.
7
6
5
4
3
2
1
0
R
0
W
Reset
0
0
0
0
0
0
0
0
Figure 13-9. SCI Status Register 2 (SCIxS2)
Table 13-6. SCIxS2 Field Descriptions
Field
Description
7
LBKDIF
LIN Break Detect Interrupt Flag. LBKDIF is set when the LIN break detect circuitry is enabled and a LIN break
character is detected. LBKDIF is cleared by writing a 1 to it.
0 No LIN break character has been detected.
1 LIN break character has been detected.
6
RXEDGIF
RxD Pin Active Edge Interrupt Flag. RXEDGIF is set when an active edge (falling if RXINV = 0, rising if RXINV=1)
on the RxD pin occurs. RXEDGIF is cleared by writing a 1 to it.
0 No active edge on the receive pin has occurred.
1 An active edge on the receive pin has occurred.
4
RXINV
1
Receive Data Inversion. Setting this bit reverses the polarity of the received data input.
0 Receive data not inverted
1 Receive data inverted
3
RWUID
Receive Wake Up Idle Detect. RWUID controls whether the idle character that wakes up the receiver sets the
IDLE bit.
0 During receive standby state (RWU = 1), the IDLE bit does not get set upon detection of an idle character.
1 During receive standby state (RWU = 1), the IDLE bit gets set upon detection of an idle character.
2
BRK13
Break Character Generation Length. BRK13 selects a longer transmitted break character length. Detection of a
framing error is not affected by the state of this bit.
0 Break character is transmitted with length of 10 bit times (11 if M = 1)
1 Break character is transmitted with length of 13 bit times (14 if M = 1)
Table 13-5. SCIxS1 Field Descriptions (continued)
Field
Description