s908gz60cfa Freescale Semiconductor, Inc, s908gz60cfa Datasheet - Page 211

• Manufacturer Part Number: s908gz60cfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

NF — Receiver Noise Flag Bit
FE — Receiver Framing Error Bit
PE — Receiver Parity Error Bit
14.8.5 ESCI Status Register 2
ESCI status register 2 (SCS2) contains flags to signal these conditions:
BKF — Break Flag Bit
Freescale Semiconductor
In applications that are subject to software latency or in which it is important to know which byte is lost
due to an overrun, the flag-clearing routine can check the OR bit in a second read of SCS1 after
reading the data register.
This clearable, read-only bit is set when the ESCI detects noise on the RxD pin. NF generates an NF
CPU interrupt request if the NEIE bit in SCC3 is also set. Clear the NF bit by reading SCS1 and then
reading the SCDR. Reset clears the NF bit.
This clearable, read-only bit is set when a 0 is accepted as the stop bit. FE generates an ESCI 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.
This clearable, read-only bit is set when the ESCI 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.
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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 CPU 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. Reset clears the BKF bit.
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
Break character detected
Incoming data
Address:
Reset:
Read:
Write:
MC68HC908GZ60 • MC68HC908GZ48 • MC68HC908GZ32 Data Sheet, Rev. 6
$0017
Bit 7
0
0
Figure 14-15. 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
I/O Registers
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