SIC63616-(Rev. 1.0) NO. P123
3240-0412
4.10.4 Operating mode of serial interface
The serial interface supports three operating modes: master mode, slave mode and SPI slave mode.
Master mode
Master mode is provided to use the S1C63616 as the master device for serial transfer. In this mode, the
serial interface uses the internal clock supplied from the clock manager as the synchronous clock for
serial transfer. The synchronous clock is also output from the SCLK (P20) terminal to the slave device.
The ready signal sent from the slave device should be input through an I/O port (in input mode) and it
should be read with software to control data transfer.
The S1C63616 set to master mode is also used as an SPI master device. The SS (Slave Select) signal
should be output by controlling an I/O port (in output mode) with software.
Slave mode
Slave mode is provided to use the S1C63616 as a slave device for serial transfer. In this mode, the serial
interface inputs the synchronous clock that is sent by the external master device from the SCLK terminal
to perform serial transfer. For the master device to control data transfer, the serial interface can output a
ready signal indicating that it is ready to transfer from the SRDY terminal by hardware control.
SPI slave mode
SPI slave mode is provided to use the S1C63616 as an SPI slave device. In this mode, the serial interface
inputs the synchronous clock that is sent by the external master device from the SCLK terminal to per-
form serial transfer. The SPI master device outputs the SS (Slave Select) signal to select a slave device.
SPI slave mode supports the SS signal input.
Sample basic serial connection diagrams are shown in Figure 4.10.4.1.
S1C63616
External
slave device
(a-1) Master mode
SCLK
SOUT
SIN
Pxx
CLK
SOUT
SIN
READY
S1C63616
SPI slave
device
(a-2) Master mode (SPI)
SCLK
SOUT
SIN
Pxx
CLK
SDO
SDI
SS
S1C63616
External
master device
(b) Slave mode
SCLK
SOUT
SIN
SRDY
CLK
SOUT
SIN
READY input
S1C63616
SPI master
device
(c) SPI slave mode
SCLK
SOUT
SIN
SS
SCLK
SDO
SDI
SS
Figure 4.10.4.1 Sample basic connection of serial input/output terminals
The SMOD, ENCS and ESREADY registers are used for setting the mode.
Master mode:
SMOD = "1", ENCS = "0", ESREADY = "0"
Slave mode:
SMOD = "0", ENCS = "1", ESREADY = "1"
SPI slave mode: SMOD = "0", ENCS = "1", ESREADY = "0"
Table 4.10.4.1 lists the combination of mode settings and used terminal configurations.