LAPIS Semiconductor ML610421, User Manual, Page: 190 / 437

ML610Q421/ML610Q422/ML610421 User’s Manual
Chapter 13 Synchronous Serial Port
13 – 10
13.3.3 Transmit/Receive Operation
When “1” is written to the S0MD1 bit and “1” is written to the S0MD0 bit of the serial mode register (SIO0MOD0), this
LSI is set to a transmit/receive mode.
When the S0EN bit of the serial port control register (SIO0CON) is set to “1”, transmission/reception starts. When
transmission/reception of 8/16-bit data terminates, a synchronous serial port interrupt (SIO0INT) occurs and the S0EN
bit is set to “0”.
Receive data is input from the tertiary function pins (P40/SIN0 or P44/SIN0) of GPIO, and transmit data is output from
the tertiary function pins (P42/SOUT0 or P46/SOUT0) of GPIO
When an internal clock is selected in the serial port mode register (SIO0MD1), the LSI is set to a master mode and when
an external clock (P41/SCK0 or P45/SCK0) is selected, the LSI is set ot a slave mode.
The serial port mode register (SIO0MOD0) enables selection of MSB first or LSB first.
The receive data input pin (P40/SIN0 or P44/SIN0), the transmit data output pin (P42/SOUT0 or P46/SOUT0), and
transfer clock input/output pin (P41/SCK0 or P45/SCK0) must be set to the tertiary function.
Figure 13-6 shows the transmit/receive operation waveforms of the synchronous serial port (16-bit length, LSB first,
clock types 0).
Figure 13-6 Transmit/Receive Operation Waveforms of Synchronous Serial Port
(16-bit Length, LSB first, Clock Type 0)
15
S0EN
0 1 2 3 12 13 15 14
Receive data
SCK0
SIN0
Shift register
SIO0INT
0 1 2 3 13 14
SIO0RCH, L
15
SOUT0
0 1 2 3 12 13 14
Transmit data
SIO0TRH,L
12