20 GENERAL-PURPOSE SERIAL INTERFACE (FSIO)
20-26
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
EPR is used to select whether receive data is to be checked for parity, and whether a parity bit is to be
added to transmit data. When EPR is set to 1, the receive data is checked for parity. A parity bit is au-
tomatically added to the transmit data. When EPR is set to 0, parity is not checked and no parity bit is
added.
EPR is only effective in asynchronous mode. Settings of EPR have no effect in clock-synchronized
mode.
D4
PMD: Parity Mode Select Bit
Selects an odd or even parity for asynchronous transfer.
1 (R/W): Odd parity
0 (R/W): Even parity (default)
Odd parity is selected by writing 1 to PMD, and even parity is selected by writing 0. Parity check and
the addition of a parity bit are only effective in asynchronous transfers in which EPR is set to 1. If EPR
= 0, PMD is ineffective.
D3
STPB: Stop Bit Select Bit
Selects a stop-bit length for asynchronous transfer.
1 (R/W): 2 bits
0 (R/W): 1 bit (default)
STPB is only valid in asynchronous mode. Two stop bits are selected by writing 1 to STPB, and one
stop bit is selected by writing 0. The start bit is fixed at 1 bit.
Settings of STPB are ignored in clock-synchronized mode.
D2
SSCK: Input Clock Select Bit
Selects the clock source for asynchronous transfer.
1 (R/W): SCLK
x
(external clock)
0 (R/W): Internal clock (default)
During operation in asynchronous mode, this bit is used to select the clock source between an internal
clock (output from the baud-rate timer) and an external clock (input from the SCLK
x
pin). An external
clock is selected by writing 1 to this bit, and an internal clock is selected by writing 0.
D[1:0]
SMD[1:0]: Transfer Mode Select Bits
Sets the transfer mode of the serial interface as shown in the table below.
10.3 Setting of Transfer Mode
Table 20.
SMD[1:0]
Transfer mode
0x3
8-bit asynchronous mode
0x2
7-bit asynchronous mode
0x1
Clock-synchronized slave mode
0x0
Clock-synchronized master mode
(Default: 0x0)
SMD[1:0] can be read as well as written.
When using the IrDA interface, always be sure to set asynchronous mode for the transfer mode.
FSIO Ch.
x
IrDA Registers (FSIO_IRDA
x
)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
FSIO Ch.
x
IrDA Register
(FSIO_IRDA
x
)
0x300704
0x300714
(8 bits)
D7
SRDYCTL
#SRDY control
1 High mask
0 Normal
0
R/W Writing is disabled
when SIOADV = 0.
D6–5 FIFOINT
[1:0]
Receive buffer full interrupt
timing
FIFOINT[1:0]
Receive level
0x0 R/W
0x3
0x2
0x1
0x0
4
3
2
1
D4
DIVMD
Async clock division ratio
1 1/8
0 1/16
0
R/W
D3
IRTL
IrDA I/F output logic inversion
1 Inverted
0 Direct
0
R/W Valid only in async
mode.
D2
IRRL
IrDA I/F input logic inversion
1 Inverted
0 Direct
0
R/W
D1–0 IRMD[1:0]
Interface mode select
IRMD[1:0]
I/F mode
0x0 R/W
0x3
0x2
0x1
0x0
reserved
IrDA 1.0
reserved
General I/F