MC68HC08AS32 Datasheet, PDF (268/394 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Serial Communications Interface (SCI)
FE — Receiver Framing Error Bit
This clearable, read-only bit is set when a logic 0 is accepted as the
stop bit. FE generates an SCI error CPU interrupt request if the FEIE
bit in SCC3 also is set. Clear the FE bit by reading SCS1 with FE set
and then reading the SCDR. Reset clears the FE bit.
1 = Framing error detected
0 = No framing error detected
PE — Receiver Parity Error Bit
This clearable, read-only bit is set when the SCI detects a parity error
in incoming data. PE generates a PE CPU interrupt request if the
PEIE bit in SCC3 is also set. Clear the PE bit by reading SCS1 with
PE set and then reading the SCDR. Reset clears the PE bit.
1 = Parity error detected
0 = No parity error detected
NORMAL FLAG CLEARING SEQUENCE
BYTE 1
READ SCS1
SCRF = 1
OR = 0
READ SCDR
BYTE 1
BYTE 2
READ SCS1
SCRF = 1
OR = 0
READ SCDR
BYTE 2
BYTE 3
DELAYED FLAG CLEARING SEQUENCE
READ SCS1
SCRF = 1
OR = 0
READ SCDR
BYTE 3
BYTE 4
BYTE 1
BYTE 2
READ SCS1
SCRF = 1
OR = 0
READ SCDR
BYTE 1
BYTE 3
READ SCS1
SCRF = 1
OR = 1
READ SCDR
BYTE 3
BYTE 4
Figure 17-10. Flag Clearing Sequence
Advance Information
268
Serial Communications Interface (SCI)
MC68HC08AS32 — Rev. 3.0
MOTOROLA