Serial Communications Interface Module (SCI)

INTERNAL BUS

SCP1

SCP0

⎟ 4

fOP

ERROR CPU INTERRUPT REQUEST

CPU INTERRUPT REQUEST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCR2

 

 

SCR1

 

 

SCR0

PRE-

BAUD

⎟ 16

SCALER

DIVIDER

 

DATA

PTF4/RxD RECOVERY

ALL 0s

BKF

RPF

M

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WAKE

 

 

 

 

 

 

 

 

 

 

 

 

WAKEUP

 

 

 

 

ILTY

 

 

 

 

 

LOGIC

 

 

 

 

 

 

 

 

PEN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PARITY

 

 

 

 

PTY

 

 

 

 

 

CHECKING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IDLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ILIE

 

 

 

 

 

 

 

 

SCRF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCRIE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OR

ORIE

NF

NEIE

FE

FEIE

PE

PEIE

SCI DATA REGISTER

 

 

STOP

 

 

 

 

 

 

 

 

11-BIT

 

 

 

 

START

 

 

 

 

RECEIVE SHIFT REGISTER

 

 

 

H

8

7

6

5

 

4

 

3

2

1

0

L

 

 

ALL 1s

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MSB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SCRF

 

 

 

RWU

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IDLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ILIE

SCRIE

OR

ORIE

NF

NEIE

FE

FEIE

PE

PEIE

Figure 13-6. SCI Receiver Block Diagram

13.3.3.1 Character Length

The receiver can accommodate either 8-bit or 9-bit data. The state of the M bit in SCI control register 1 (SCC1) determines character length. When receiving 9-bit data, bit R8 in SCI control register 2 (SCC2) is the ninth bit (bit 8). When receiving 8-bit data, bit R8 is a copy of the eighth bit (bit 7).

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

164

Freescale Semiconductor

Page 163 Page 165
Page 164
Image 164
Freescale Semiconductor MC68HC908MR32, MC68HC908MR16 manual SCI Receiver Block Diagram
Page 163 Page 165

MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

One of the standout features of the MC68HC908MR series is its CMOS technology, which enhances performance while minimizing power consumption. This makes these microcontrollers suitable for battery-operated devices. They operate at a maximum clock frequency of 2 MHz and offer a 16-bit architecture, providing a solid balance between processing power and efficiency.

The MC68HC908MR32 variant is equipped with 32KB of flash memory, which allows for the storage of complex programs and extensive data handling. In contrast, the MC68HC908MR16 features 16KB of flash memory, making it ideal for simpler applications. Both microcontrollers also come with 1KB of RAM, enabling efficient data processing and real-time operations.

Another significant characteristic of these microcontrollers is their integrated peripherals. They come with multiple input/output (I/O) pins, which allow for connectivity with various sensors and actuators. The built-in timer systems offer precise timing control for automotive and industrial applications, while the Analog-to-Digital Converter (ADC) provides essential conversion capabilities for various analog signals.

For communication purposes, the MC68HC908MR series includes a serial communication interface, enabling easy integration with other devices and systems. This versatility facilitates the development of complex systems that require interaction with external components.

Security is another crucial aspect of these microcontrollers. They have built-in fail-safe mechanisms to ensure reliable operation under various conditions, making them suitable for critical systems. Additionally, their robust architecture helps to safeguard against potential disruptions or attacks.

In summary, Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are key players in the embedded systems landscape. Their blend of power efficiency, integrated features, and scalability ensures they remain relevant for a wide array of applications, making them a favored choice among engineers and developers looking for dependable solutions in a competitive market.
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