mc68hc11d0cfn2 Freescale Semiconductor, Inc, mc68hc11d0cfn2 Datasheet - Page 83

• Manufacturer Part Number: mc68hc11d0cfn2
• Description: M68hc11 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

6.8 Status Flags and Interrupts
MC68HC711D3 — Rev. 2
MOTOROLA
EXTAL
XTAL
The SCI transmitter has two status flags. These status flags can be read by
software (polled) to tell when the corresponding condition exists. Alternatively, a
local interrupt enable bit can be set to enable each of these status conditions to
generate interrupt requests when the corresponding condition is present. Status
flags are automatically set by hardware logic conditions, but must be cleared by
software, which provides an interlock mechanism that enables logic to know when
software has noticed the status indication. The software clearing sequence for
these flags is automatic — functions that are normally performed in response to the
status flags also satisfy the conditions of the clearing sequence.
CLOCK GENERATOR
OSCILLATOR
AND
(÷ 4)
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 6-8. SCI Baud Rate Diagram
Serial Communications Interface (SCI)
E
AS
Go to: www.freescale.com
÷ 2
÷ 2
÷ 2
÷ 2
÷ 2
÷ 2
÷ 2
0:0
SCR2–SCR0
0:0:0
0:0:1
0:1:0
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
÷ 3
0:1
INTERNAL BUS CLOCK (PH2)
÷ 4
Serial Communications Interface (SCI)
BAUD RATE
BAUD RATE
TRANSMIT
RECEIVE
1:0
÷ 16
(1X)
(16X)
SCI
SCI
÷ 13
Status Flags and Interrupts
1:1
SCP1 AND SCP0
Data Sheet
83