Renesas 7542 Manual page 131

7542 Group
Notes on Serial I/O1
1. I/O pin function when serial I/O1 is enabled.
The pin functions of P1 /S
2 CLK1
follows according to the setting values of a serial I/O1 mode selec-
tion bit (bit 6 of serial I/O1 control register (address 1A
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" : P1 pin turns into an output pin of a synchronous clock.
2
"1" : P1 pin turns into an input pin of a synchronous clock.
2
• Setup of a S output enable bit (SRDY)
RDY1
"0" : P1 pin can be used as a normal I/O pin.
3
"1" : P1 pin turns into a S
3 RDY1
(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": P1 pin can be used as a normal I/O pin.
2
"1": P1 pin turns into an input pin of an external clock.
2
• When clock asynchronous (UART) type serial I/O is selected, it
functions P1 pin. It can be used as a normal I/O pin.
3
Note on Bus Collision Detection
When serial I/O1 is operating at half-duplex communication, set
bus collision detection interrupt to be disabled.
Rev.3.02 Oct 31, 2006
REJ03B0006-0302
and P1 /S are switched to as
3 RDY1
)) and a
16
output pin.
Page 131 of 134
Notes on Serial I/O2
1. I/O pin function when serial I/O2 is enabled
The pin functions of P0 /S
6 CLK2
follows according to the setting values of a serial I/O2 mode selec-
tion bit (bit 6 of serial I/O2 control register (address 30
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" : P0 pin turns into an output pin of a synchronous clock.
6
"1" : P0 pin turns into an input pin of a synchronous clock.
6
• Setup of a S output enable bit (SRDY)
RDY2
"0" : P0 pin can be used as a normal I/O pin.
7
"1" : P0 pin turns into a S
7 RDY2
(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": P0 pin can be used as a normal I/O pin.
6
"1": P0 pin turns into an input pin of an external clock.
6
• When clock asynchronous (UART) type serial I/O is selected, it
functions P0 pin. It can be used as a normal I/O pin.
7
and P0 /S are switched to as
7 RDY2
)) and a
16
output pin.