11 SYNCHRONOUS SERIAL INTERFACE (SPI)
11-12
Seiko epson Corporation
S1C17F13 TeChniCal Manual
(Rev. 1.0)
Bit 1
SFTRST
This bit issues software reset to the SPI.
1 (W):
Issue software reset
0 (W):
Ineffective
1 (R):
Software reset is executing.
0 (R):
Software reset has finished. (During normal operation)
Setting this bit resets the SPI shift register and transfer bit counter. This bit is automatically cleared
after the reset processing has finished.
Bit 0
MODen
This bit enables the SPI operations.
1 (R/W): Enable SPI operations (In master mode, the operating clock is supplied.)
0 (R/W): Disable SPI operations (In master mode, the operating clock is stopped.)
Note: If the SPI
n
CTL.MODEN bit is altered from 1 to 0 during sending/receiving data, the data being
sent/received cannot be guaranteed. When setting the SPI
n
CTL.MODEN bit to 1 again after that,
be sure to write 1 to the SPI
n
CTL.SFTRST bit as well.
SPi Ch.
n
Transmit Data Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
SPI
n
TXD
15–8 –
0x00
–
R
–
7–0 TXD[7:0]
0x00
H0
R/W
Bits 15–8 Reserved
Bits 7–0
TXD[7:0]
Data can be written to the transmit data buffer through these bits.
In master mode, writing to these bits starts data transfer.
Transmit data can be written when the SPI
n
INTF.TBEIF bit = 1 regardless of whether data is being
output from the SDO
n
pin or not.
Note: Be sure to avoid writing to the SPI
n
TXD register when the SPI
n
INTF.TBEIF bit = 0. Otherwise,
transfer data cannot be guaranteed.
SPi Ch.
n
Receive Data Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
SPI
n
RXD
15–8 –
0x00
–
R
–
7–0 RXD[7:0]
0x00
H0
R
Bits 15–8 Reserved
Bits 7–0
RXD[7:0]
The receive data buffer can be read through these bits. Received data can be read when the SPI
n
INTF.
RBFIF bit = 1 regardless of whether data is being input from the SDI
n
pin or not.
Note: The SPI
n
RXD.RXD[7:0] bits are cleared to 0x00 when 1 is written to the SPI
n
CTL.MODEN bit or
the SPI
n
CTL.SFTRST bit.
SPi Ch.
n
interrupt Flag Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
SPI
n
INTF
15–8 –
0x00
–
R
–
7–4 –
0x0
–
R
3
BSY
0
H0
R
2
TENDIF
0
H0/S0
R/W Cleared by writing 1.
1
RBFIF
0
H0/S0
R
Cleared by reading the SPI
n
RXD
register.
0
TBEIF
1
H0/S0
R
Cleared by writing to the SPI
n
TXD
register.