20 GENERAL-PURPOSE SERIAL INTERFACE (FSIO)
20-2
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
FSIO Pins
20.2
Table 20.2.1 lists the I/O pins provided for the FSIO module.
2.1 List of FSIO Pins
Table 20.
Pin name
I/O
Qty
Function
SIN0
SIN1
I
2 FSIO serial data input pin
Inputs serial data.
SOUT0
SOUT1
O
2 FSIO serial data output pin
Outputs serial data.
SCLK0
SCLK1
I/O
2 FSIO clock input/output pin
Inputs or outputs a clock.
In clock-synchronized slave mode, it is used as a clock input pin; in clock-synchronized
master mode, it is used as a clock output pin.
In asynchronous mode, this pin is used as a clock input when an external clock is used.
This pin can be used as an I/O port when the internal clock is used.
#SRDY0
#SRDY1
I/O
2 FSIO ready-signal input/output pin
Inputs or outputs the ready signal used in clock-synchronized mode.
In clock-synchronized slave mode, it is used as the ready-signal output pin; in clock-syn-
chronized master mode, it is used as the ready-signal input pin.
This pin can be used as an I/O port in asynchronous mode.
The FSIO pins (SIN
x
, SOUT
x
, SCLK
x
, #SRDY
x
) are shared with I/O ports and are initially set as general purpose
I/O port pins. The pin functions must be switched using the port function select bits to use the general purpose I/O
port pins as FSIO pins.
For detailed information on pin function switching, see the “I/O Ports (GPIO)” chapter.
FSIO Operating Clock
20.3
FSIO Ch.0 and Ch.1 use PCLK1 and PCLK2 as the operating clock, respectively. Therefore, PCLK1 and/or PCLK2
must be supplied from the CMU before starting the FSIO including setting the control registers. For more informa-
tion on the PCLK1/PCLK2 supply, refer to the “Clock Management Unit (CMU).”
Mode Settings
20.4
Interface Mode and Transfer Mode
20.4.1
The interface type and transfer mode of the serial interface can be configured using SMD[1:0]/FSIO_CTL
x
register
and IRMD[1:0]/FSIO_IRDA
x
register individually for each channel as shown in the table below.
4.1.1 Interface and Transfer Mode Settings
Table 20.
IRMD[1:0]
SMD[1:0]
Interface mode
Transfer mode
0x2
0x3
IrDA mode
8-bit asynchronous mode (IrDA I/F)
0x2
7-bit asynchronous mode (IrDA I/F)
0x0
0x3
Normal mode
8-bit asynchronous mode (normal I/F)
0x2
7-bit asynchronous mode (normal I/F)
0x1
Clock-synchronized slave mode
0x0
Clock-synchronized master mode
Other
Reserved
At initial reset, SMD[1:0] and IRMD[1:0] are both set to 0 (clock-synchronized master mode).
When using the IrDA interface, set the transfer mode for the asynchronous 7-bit or asynchronous 8-bit mode.
The input/output pins are configured differently, depending on the transfer mode. The pin configuration in each
mode is shown in Table 20.4.1.2.