mc68hc11k4vfu4 Freescale Semiconductor, Inc, mc68hc11k4vfu4 Datasheet - Page 49

• Manufacturer Part Number: mc68hc11k4vfu4
• Description: 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

7 Serial Communications Interface
M68HC11 K Series
MC68HC11KTS/D
The SCI, a universal asynchronous receiver transmitter (UART) serial communications interface, is one
of two independent serial I/O subsystems in M68HC11 K-series MCUs. Rearranging registers and con-
trol bits used in previous M68HC11 family devices has enhanced the existing SCI system and added
new features, which include the following:
The enhanced baud rate generator is shown in the following diagram. Refer to Table 7 for standard val-
ues.
EXTAL
• A 13-bit modulus prescaler that allows greater baud rate control
• A new idle mode detect, independent of preceding serial data
• A receiver active flag
• Hardware parity for both transmitter and receiver
SCBDH/L SCI BAUD CONTROL
13-BIT COUNTER
13-BIT COMPARE
Figure 9 SCI Baud Generator Circuit Diagram
RESET
=
2
PHASE 2 CLOCK
INTERNAL
SYNCH
16
RECEIVER
BAUD RATE
CLOCK
TRANSMITTER
BAUD RATE
CLOCK
MOTOROLA
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