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R01UH0336EJ0102 Rev.1.02
Page 1248 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 22 Synchronous/Asynchronous Serial Interface H (UARTH)
22.6.3
Handshake Mode
In this mode, the receive enable signal (URTHnRTS) and transmit enable
signal (URTHnCTS) are used for handshaking in data transmission and
reception.
Transmission
After data are written to the transmit data register, the data are transmitted if
the URTHnCTS signal input is at the active level. If the URTHnCTS signal is at
the inactive level, data transmission will be suspended.
The data are transmitted immediately when the URTHnCTS signal goes to the
active level. If the URTHnCTS signal is then changed to the inactive level while
transmission is in progress, 1 frame of data will still be transmitted.
(a)
Example of handshake signals (to wait for permission from URTHnCTS)
in transmission
(b)
Example of handshake signals (to wait for writing of data) in
transmission
State
of operation
URTHNnTXD pin
URTHnCTS pin
(input)
URTHnTIT
interrupt
State of the transmit
data register
URTHnTXE bit = 1
Waiting for CTS
Initialization
Data transmission
Waiting for CTS
Data transmission
Writing to the transmit data register
Empty
Empty
Writing to the transmit data register
Writing to the transmit data register
Full
Full
Empty
L
URTHNnTXD pin
URTHnCTS pin
(input)
URTHnTIT
interrupt
State of the transmit
data register
Initialization
URTHnTXE bit = 1
State of operation
Waiting for CTS
Data transmission
Data transmission
Waiting
for data
Empty
Full
Empty
Empty
Full
Writing to the transmit data register
Writing to the transmit data register
Writing to the transmit data register
Содержание V850 Series
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