s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 143

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

NF — Receiver Noise Flag Bit
FE — Receiver Framing Error Bit
PE — Receiver Parity Error Bit
13.8.5 ESCI Status Register 2
ESCI status register 2 (SCS2) contains flags to signal these conditions:
BKF — Break Flag Bit
RPF — Reception in Progress Flag Bit
Freescale Semiconductor
This clearable, read-only bit is set when the ESCI detects noise on the RxD pin. NF generates an NF
interrupt request if the NEIE bit in SCC3 is also set. Clear the NF bit by reading SCS1 and then reading
the SCDR.
This clearable, read-only bit is set when a 0 is accepted as the stop bit. FE generates an ESCI error
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.
This clearable, read-only bit is set when the ESCI detects a parity error in incoming data. PE generates
a PE 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.
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This clearable, read-only bit is set when the ESCI 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 interrupt request. Clear BKF by reading SCS2 with BKF set and then reading the
SCDR. Once cleared, BKF can become set again only after 1s again appear on the RxD pin followed
by another break character.
This read-only bit is set when the receiver detects a 0 during the RT1 time period of the start bit search.
RPF does not generate an interrupt request. RPF is reset after the receiver detects false start bits
(usually from noise or a baud rate mismatch), or when the receiver detects an idle character. Polling
RPF before disabling the ESCI module or entering stop mode can show whether a reception is in
progress.
1 = Noise detected
0 = No noise detected
1 = Framing error detected
0 = No framing error detected
1 = Parity error detected
0 = No parity error detected
1 = Break character detected
0 = No break character detected
1 = Reception in progress
0 = No reception in progress
Break character detected
Reception in progress
Reset:
Read:
Write:
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
Bit 7
0
0
Figure 13-14. ESCI Status Register 2 (SCS2)
= Unimplemented
6
0
0
5
0
0
4
0
0
3
0
0
2
0
0
BKF
1
0
Bit 0
RPF
0
Registers
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