Operation In Clock Synchronous Mode (Operation Mode 2) - Fujitsu MB90895 Series Hardware Manual

15.6.2 Operation in Clock Synchronous Mode
(Operation Mode 2)
When the UART1 is used in operation mode 2, the transfer mode is clock synchronous.
I Operation in Clock Synchronous Mode
G
Format of transmit/receive data
In the synchronous mode, 8-bit data is transmitted/received on LSB-first.The start and stop bits are not
added to the transmit/receive data.
shows the data format for the clock synchronous mode.
Figure 15.6-5 Format of Transmit/Receive Data (Operation Mode 2)
Transmission by serial clock output
Transmission data
Reception by serial clock input
Reception data
G
Clock Supply
In the clock synchronous mode, count of clocks equal to the transmit and receive bits count must be
supplied.
• When the internal clock (dedicated baud rate generator or internal timer) has already selected (SMR1
register bit 5 to 3: CS2 to CS0 = "000
clock for data reception is generated automatically.
• When the external clock has already selected (SMR1 register bit 5 to 3: CS2 to CS0 = "111
for exact one byte must be supplied from outside after ensuring that data is present (SSR1 register bit
SCK1 output
SOT1
1
(LSB)
writing
TXE
SCK1 input
SIN1
1
(LSB)
RXE
reading
0 1 1 0 0 1 0
Transmission data
0 1 1 0 0 1 0
Reception data
" to "101 " or "110
B B B
CHAPTER 15 UART1
Mark level
(MSB)
Mark level
(MSB)
") and data is transmitted, the synchronous
"), the clock
B
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