7721 Datasheet, PDF (219/577 Pages) List of Unclassifed Manufacturers – H Bridge Power Module

SERIAL I/O
11.3 Clock synchronous serial I/O mode
11.3 Clock synchronous serial I/O mode
Table 11.3.1 lists the performance overview in the clock synchronous serial I/O mode, and Table 11.3.2 lists
the functions of I/O pins in this mode.
Table 11.3.1 Performance overview in clock synchronous serial I/O mode
Item
Functions
Transfer data format
Transfer data has a length of 8 bits.
LSB first
Transfer rate _{When selecting internal clock} BRGi’s output divided by 2
When selecting external clock Maximum 5 Mbps
____
____
Transmit/Receive control
CTS function or RTS function can be selected by software.
Table 11.3.2 Functions of I/O pins in clock synchronous serial I/O mode
Pin name
Functions
Method of selection
TxDi (P83, P87) Serial data output
(Note)
(Dummy data is output when performing only reception.)
RxDi (P82, P86) Serial data input
Port P8 direction register^U1’s corresponding bit = “0”
CLKi (P81, P85)
(Can be used as an I/O port when performing only transmission.)
Transfer clock output Internal/External clock select bit^U2 = “0”
___ ___
CTSi/RTSi
(P80, P84)
Transfer clock input
____
CTS input
____
RTS output
Internal/External clock select bit = “1”
____ ____
CTS/RTS select bit^U3 = “0”
____ ____
CTS/RTS select bit = “1”
Port P8 direction register^U1: address 1416
Internal/External
____ ____
clock
select
bit^U2:
bit
3
at
addresses
3016,
3816
CTS/RTS select bit^U3: bit 2 at addresses 3416, 3C16
Note: The TxDi pin outputs “H” level until transmission starts after UARTi’s operating mode is selected.
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7721 Group User’s Manual