7542 Group
Rev.3.02
Oct 31, 2006
Page 131 of 134
REJ03B0006-0302
Notes on Serial I/O1
1. I/O pin function when serial I/O1 is enabled.
The pin functions of P12/SCLK1 and P13/SRDY1 are switched to as
follows according to the setting values of a serial I/O1 mode selec-
tion bit (bit 6 of serial I/O1 control register (address 1A16)) and a
serial I/O1 synchronous clock selection bit (bit 1 of serial I/O1 con-
trol register).
(1) Serial I/O1 mode selection bit → “1” :
Clock synchronous type serial I/O is selected.
Setup of a serial I/O1 synchronous clock selection bit
“0” : P12 pin turns into an output pin of a synchronous clock.
“1” : P12 pin turns into an input pin of a synchronous clock.
Setup of a SRDY1 output enable bit (SRDY)
“0” : P13 pin can be used as a normal I/O pin.
“1” : P13 pin turns into a SRDY1 output pin.
(2) Serial I/O1 mode selection bit → “0” :
Clock asynchronous (UART) type serial I/O is selected.
Setup of a serial I/O1 synchronous clock selection bit
“0”: P12 pin can be used as a normal I/O pin.
“1”: P12 pin turns into an input pin of an external clock.
When clock asynchronous (UART) type serial I/O is selected, it
functions P13 pin. It can be used as a normal I/O pin.
Note on Bus Collision Detection
When serial I/O1 is operating at half-duplex communication, set
bus collision detection interrupt to be disabled.
Notes on Serial I/O2
1. I/O pin function when serial I/O2 is enabled
The pin functions of P06/SCLK2 and P07/SRDY2 are switched to as
follows according to the setting values of a serial I/O2 mode selec-
tion bit (bit 6 of serial I/O2 control register (address 3016)) and a
serial I/O2 synchronous clock selection bit (bit 2 of serial I/O2 con-
trol register).
(1) Serial I/O2 mode selection bit → “1” :
Clock synchronous type serial I/O is selected.
Setup of a serial I/O2 synchronous clock selection bit
“0” : P06 pin turns into an output pin of a synchronous clock.
“1” : P06 pin turns into an input pin of a synchronous clock.
Setup of a SRDY2 output enable bit (SRDY)
“0” : P07 pin can be used as a normal I/O pin.
“1” : P07 pin turns into a SRDY2 output pin.
(2) Serial I/O2 mode selection bit → “0” :
Clock asynchronous (UART) type serial I/O is selected.
Setup of a serial I/O2 synchronous clock selection bit
“0”: P06 pin can be used as a normal I/O pin.
“1”: P06 pin turns into an input pin of an external clock.
When clock asynchronous (UART) type serial I/O is selected, it
functions P07 pin. It can be used as a normal I/O pin.