MC908MR8MPE Freescale Semiconductor, MC908MR8MPE Datasheet - Page 253

• Manufacturer Part Number: MC908MR8MPE
• Description: IC MCU 8BIT 8K FLASH 28-PDIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908MR8MPE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 12
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

13.4.2.3 Break Characters
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor
At the start of a transmission, transmitter control logic automatically
loads the transmit shift register with a preamble of logic 1s. After the
preamble shifts out, control logic transfers the SCDR data into the
transmit shift register. A logic 0 start bit automatically goes into the least
significant bit (LSB) position of the transmit shift register. A logic 1 stop
bit goes into the most significant bit (MSB) position.
The SCI transmitter empty bit, SCTE, in SCS1 becomes set when the
SCDR transfers a byte to the transmit shift register. The SCTE bit
indicates that the SCDR can accept new data from the internal data bus.
If the SCI transmit interrupt enable bit, SCTIE, in SCC2 is also set, the
SCTE bit generates a transmitter CPU interrupt request.
When the transmit shift register is not transmitting a character, the
PTB1/TxD pin goes to the idle condition, logic 1. If at any time software
clears the ENSCI bit in SCI control register 1 (SCC1), the transmitter and
receiver relinquish control of the port B pins.
Writing a logic 1 to the send break bit, SBK, in SCC2 loads the transmit
shift register with a break character. A break character contains all logic
0s and has no start, stop, or parity bit. Break character length depends
on the M bit in SCC1. As long as SBK is at logic 1, transmitter logic
continuously loads break characters into the transmit shift register. After
software clears the SBK bit, the shift register finishes transmitting the
last break character and then transmits at least one logic 1. The
automatic logic 1 at the end of a break character guarantees the
recognition of the start bit of the next character.
The SCI recognizes a break character when a start bit is followed by
eight or nine logic 0 data bits and a logic 0 where the stop bit should be.
Serial Communications Interface (SCI)
Serial Communications Interface (SCI)
Functional Description
Technical Data
253