mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 132

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Serial Communications Interface Module (SCI)
PE — Receiver Parity Error Bit
12.7.5 SCI Status Register 2
SCI status register 2 (SCS2) contains flags to signal these conditions:
BKF — Break Flag Bit
132
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.
•
•
This clearable, read-only bit is set when the SCI detects a break character on the RxD pin. In SCS1,
the FE and SCRF bits are also set. In 9-bit character transmissions, the R8 bit in SCC3 is cleared. BKF
does not generate a CPU interrupt request. Clear BKF by reading SCS2 with BKF set and then reading
1 = Parity error detected
0 = No parity error detected
Break character detected
Incoming data
Address:
Reset:
Read:
Write:
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
BYTE 1
BYTE 1
$0017
Bit 7
0
0
Figure 12-15. SCI Status Register 2 (SCS2)
READ SCS1
READ SCDR
= Unimplemented
SCRF = 1
Figure 12-14. Flag Clearing Sequence
BYTE 1
OR = 0
6
0
0
DELAYED FLAG CLEARING SEQUENCE
NORMAL FLAG CLEARING SEQUENCE
READ SCDR
READ SCS1
BYTE 2
BYTE 2
SCRF = 1
BYTE 1
OR = 0
5
0
0
READ SCDR
READ SCS1
SCRF = 1
BYTE 2
4
0
0
OR = 0
BYTE 3
BYTE 3
3
0
0
READ SCDR
READ SCDR
READ SCS1
READ SCS1
SCRF = 1
SCRF = 1
2
0
0
BYTE 3
BYTE 3
OR = 1
OR = 0
BKF
BYTE 4
BYTE 4
1
0
Freescale Semiconductor
Bit 0
RPF
0