MC68HC908GR8CD Freescale Semiconductor, MC68HC908GR8CD Datasheet - Page 182

• Manufacturer Part Number: MC68HC908GR8CD
• Description: 8-bit Microcontrollers - MCU 8 Bit 8MHz
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC908GR8CD

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: HC08
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 384 B
• Operating Supply Voltage: 3 V to 5 V
• Package / Case: SOIC-28
• Mounting Style: SMD/SMT
• Data Rom Size: 64 KB
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 21
• Program Memory Type: Flash

Serial Communications Interface (SCI)
18.8.5 SCI Status Register 2
SCI status register 2 contains flags to signal the following conditions:
BKF — Break Flag Bit
182
•
•
This clearable, read-only bit is set when the SCI detects a break character on the PE1/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 PE1/RxD pin followed by another break character. Reset clears the BKF bit.
1 = Break character detected
0 = No break character detected
Break character detected
Incoming data
Address:
Reset:
Read:
Write:
BYTE 1
BYTE 1
$0017
Bit 7
0
0
READ SCS1
READ SCDR
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
SCRF = 1
Figure 18-14. SCI Status Register 2 (SCS2)
= Unimplemented
OR = 0
BYTE 1
Figure 18-13. Flag Clearing Sequence
6
0
0
READ SCDR
READ SCS1
BYTE 2
BYTE 2
DELAYED FLAG CLEARING SEQUENCE
SCRF = 1
NORMAL FLAG CLEARING SEQUENCE
BYTE 1
OR = 0
5
0
0
READ SCDR
READ SCS1
SCRF = 1
4
0
0
BYTE 2
OR = 0
3
0
0
BYTE 3
BYTE 3
2
0
0
READ SCDR
READ SCDR
READ SCS1
READ SCS1
SCRF = 1
SCRF = 1
BYTE 3
BYTE 3
OR = 1
OR = 0
BKF
1
0
BYTE 4
BYTE 4
Freescale Semiconductor
Bit 0
RPF
0