20 GENERAL-PURPOSE SERIAL INTERFACE (FSIO)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
20-1
General-Purpose Serial Interface (FSIO)
20
FSIO Module Overview
20.1
The S1C33L26 contains two channels (Ch.0 and Ch.1) of serial interfaces, the features of which are described be-
low.
• A clock-synchronized or asynchronous mode can be selected for the transfer method.
Clock-synchronized mode
Data length: 8 bits, fixed (No start, stop, and parity bits)
Receive error: An overrun error can been detected.
Asynchronous mode
Data length: 7 or 8 bits, selectable
Receive error: Overrun, framing, or parity errors can been detected.
Start bit:
1 bit, fixed
Stop bit:
1 or 2 bits, selectable
Parity bit:
Even, odd, or none, selectable
Since the transmit and receive units are independent, full-duplex communication is possible.
Supports IrDA1.0-equivalent communications by software control or using an external IrDA driver.
Internal clock or external clock is selectable.
• Baud-rate setting: Any desired baud rate can be set by selecting the baud-rate timer, or using external clock in-
put (asynchronous mode only). Up to 8 Mbps transfer in clock-synchronized mode or up to
1 Mbps transfer in asynchronous mode are possible.
• 4-byte receive buffer (FIFO) and 2-byte transmit buffer (FIFO) are built in, allowing for successive receive and
transmit operations.
• Data transfers using DMAC are possible.
• Three types of interrupts (transmit buffer empty, receive buffer full, and receive error) can be generated.
Figure 20.1.1 shows the configuration of the FSIO module (one channel).
FSIO Ch.
x
Internal bus
SCLK
x
Receive
control circuit
Receive data
buffer
(4-byte FIFO)
Interrupt
control circuit
Baud-rate
timer
#SRDY
x
SIN
x
Transmit
control circuit
Transmit data
buffer
(2-byte FIFO)
SOUT
x
Clock
control circuit
CMU
Bus I/F
ITC
1.1 FSIO Configuration
Figure 20.
Note: Two channels in the FSIO module have the same functions except for control register addresses.
For this reason, the description in this chapter applies to both FSIO channels. The ‘
x
’ in the regis-
ter name indicates the channel number (0 or 1).
Example: FSIO_CTL
x
register
Ch.0: FSIO_CTL0 register
Ch.1: FSIO_CTL1 register