Enhanced Serial Communication Interface (eSCI)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
24-9
Preliminary
OR
Overrun Flag. OR is set when software fails to read the eSCI data register before the receive shift register
receives the next frame. The OR bit is set immediately after the stop bit has been completely received for the
second frame. The data in the shift register is lost, but the data already in the eSCI data registers is not affected.
Clear OR by writing 1 to it.
0 No overrun
1 Overrun
NF
Noise Flag. NF is set when the eSCI detects noise on the receiver input. NF bit is set during the same cycle as
the RDRF flag but does not get set in the case of an overrun. Clear NF by writing 1 to it.
0 No noise
1 Noise
FE
Framing Error Flag. FE is set when a logic 0 is accepted as the stop bit. FE bit is set during the same cycle as
the RDRF flag but does not get set in the case of an overrun. Clear FE by writing 1 to it.
0 No framing error
1 Framing error
PF
Parity error flag. PF is set when the parity enable bit, PE, is set and the parity of the received data does not match
its parity bit. Clear PE by writing 1 to it.
0 No parity error
1 Parity error
bits 8–10
Reserved.
BERR
Bit Error. Indicates a bit on the bus did not match the transmitted bit. If FBR = 0, checking happens after a
complete byte has been transmitted and received again. If FBR = 1, checking happens bit by bit. This bit is used
for LIN mode only.
BERR is also set if an unrequested byte is received (i.e. a byte that is not part of an RX frame) that is not
recognized as a wakeup flag. (Because the data on the RX line does not match the idle state that was assigned
to the TX line.)
Clear BERR by writing 1 to it.
A bit error causes the LIN finite state machine (FSM) to reset unless ESCIx_LCR[LDBG] is set.
0 No bit error
1 Bit error
bits 12–14
Reserved.
RAF
Receiver Active Flag. RAF is set when the receiver detects a logic 0 during the RT1 time period of the start bit
search. RAF is cleared when the receiver detects an idle character.
0 No reception in progress
1 Reception in progress
RXRDY
Receive Data Ready. The eSCI has received LIN data. This bit is set when the ESCIx_LCR receives a byte. Clear
RXRDY by writing it with 1.
0 No receive data ready
1 Receive data ready
TXRDY
Transmit Data Ready. The LIN FSM can accept another write to ESCIx_LTR. This bit is set when the ESCIx_LTR
register becomes free. Clear TXRDY by writing it with 1.
0 ESCIx_LTR register is not free
1 ESCIx_LTR register is free
Table 24-5. ESCIx_SR Field Descriptions (continued)
Field
Description