Toshiba TLCS-900/L1 Series Manual page 133

Handshake function
Use of
can be avoided. The handshake functions is enabled or disabled by the
SC0MOD<CTSE> setting.
When the
transmission is halted until the
interrupt is generated, it requests the next data send to the CPU. The next data is
written in the transmission buffer and data sending is halted.
Though there is no RTS pin, a handshake function can be easily configured by
setting any port assigned to be the
request send data halt after data receive is completed by software in the
interrupt routine.
Timing to writing to the
transmission buffer
CTS
SIOCLK
TXDCLK
TXD
Note 1: If the signal goes high during transmission, no more data will be sent after completion of the
CTS
current transmission.
Note 2: Transmission starts on the first falling edge of the TXDCLK clock after the
pin allows data can be sent in units of one frame; thus, overrun errors
CTS
pin goes high on completion of the current data send, data
CTS 0
CTS
TMP91C824
TXD
CTS
Sender
Figure 3.9.5 Handshake Function
Send is suspended
during this period
b
13 14 15 16
a
Figure 3.9.6 (Clear to send) Timing
CTS
91C824-131
pin goes low again. However, the INTTX0
0
function. The should be output high to
RTS RTS
TMP91C824
RXD
(Any port)
RTS
Receiver
1 2 3 14
Start bit
TMP91C824
RXD
15 16 1 2 3
Bit0
signal has fallen.
CTS
2008-02-20