MC68306EH16B Freescale Semiconductor, MC68306EH16B Datasheet - Page 117

• Manufacturer Part Number: MC68306EH16B
• Description: IC MPU INTEGRATED 16MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68306EH16B

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 132-MQFP, 132-PQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• Cpu Speed: 16.7MHz
• No. Of Timers: 1
• Embedded Interface Type: UART
• Digital Ic Case Style: PQFP
• Supply Voltage Range: 4.75V To 5.25V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

6.3.2.1 TRANSMITTER. The transmitters are enabled through their respective command
registers (DUCR) located within the serial module. The serial module signals the CPU
when it is ready to accept a character by setting the transmitter-ready bit (TxRDY) in the
channel's status register (DUSR). Functional timing information for the transmitter is
shown in Figure 6-5.
The transmitter converts parallel data from the CPU to a serial bit stream on TxDx. It
automatically sends a start bit followed by the programmed number of data bits, an
optional parity bit, and the programmed number of stop bits. The least significant bit is
sent first. Data is shifted from the transmitter output on the falling edge of the clock
source.
Following transmission of the stop bits, if a new character is not available in the transmitter
holding register, the TxDx output remains high ('mark' condition), and the transmitter
empty bit (TxEMP) in the DUSR is set. Transmission resumes and the TxEMP bit is
cleared when the CPU loads a new character into the transmitter buffer (DUTB). If a
disable command is sent to the transmitter, it continues operating until the character in the
MOTOROLA
TRANSMITTER
NOTES:
4. W = WRITE
1. TIMING SHOWN FOR MR2(4) = 1
2. TIMING SHOWN FOR MR2(5) = 1
3. C = TRANSMIT CHARACTER
ENABLED
(OP0)
RTS
TxRDY
N
(SR2)
(IP0)
CTS
TxDx
CS
2
1
C1
W
MANUALLY ASSERTED
BY BIT- SET COMMAND
Freescale Semiconductor, Inc.
Figure 6-5. Transmitter Timing Diagram
For More Information On This Product,
TRANSMISSION
C1
C2
W
C1 IN
MC68306 USER'S MANUAL
Go to: www.freescale.com
C2
C3
W
START
BREAK
W
C3
C4
W
BREAK
BREAK
STOP
W
TRANSMITTED
C4
NOT
W
C5
W
C6
MANUALLY
ASSERTED
C6
6-9