MC68306 Motorola, MC68306 Datasheet - Page 113

• Manufacturer Part Number: MC68306
• Description: Integrated EC000 Processor
• Manufacturer: Motorola

6.2.4 Channel A Receiver Serial Data Input (RxDA)
This signal is the receiver serial data input for channel A. Data received on this signal is
sampled on the rising edge of the clock source, with the least significant bit received first.
6.2.5 Channel B Transmitter Serial Data Output (TxDB)
This signal is the transmitter serial data output for channel B. The output is held high
('mark' condition) when the transmitter is disabled, idle, or operating in the local loopback
mode. Data is shifted out on this signal at the falling edge of the clock source, with the
least significant bit transmitted first.
MOTOROLA
INTERFACE
TO CPU
ADDRESS BUS
CONTROL
TIRQ
IRQ
D7–D0
DATA
Figure 6-2. External and Internal Interface Signals
INTERNAL
CONTROL
LOGIC
MC68306 USER'S MANUAL
S
E
R
A
M
O
D
U
E
N
T
E
R
N
A
L
B
U
S
L
L
I
I
GENERATOR
BAUD RATE
FOUR-CHARACTER
TRANSMIT BUFFER
FOUR-CHARACTER
TRANSMIT BUFFER
TWO-CHARACTER
TWO-CHARACTER
RECEIVE BUFFER
RECEIVE BUFFER
LOGIC
. . .
COUNTER/TIMER
OUTPUT PORT
CHANNEL A
INPUT PORT
CHANNEL B
16-BIT
X2
X1/CLK
RxDA
TxDA
RxDB
TxDB
6-5